Answer:
a) Standard error = 2
b) Range = (76.08, 83.92)
c) P=0.69
d) Smaller
e) Greater
Step-by-step explanation:
a) When we have a sample taken out of the population, the standard error of the mean is calculated as:
[tex]\sigma_m=\dfrac{\sigma}{\sqrt{n}}=\dfrac{10}{\sqrt{25}}=\dfrac{10}{5}=2[/tex]
where n is te sample size (n=25) and σ is the population standard deviation (σ=10).
Then, the standard error of the classroom average score is 2.
b) The calculations for this range are the same that for the confidence interval, with the difference that we know the population mean.
The population standard deviation is know and is σ=10.
The population mean is M=80.
The sample size is N=25.
The standard error of the mean is σM=2.
The z-value for a 95% confidence interval is z=1.96.
The margin of error (MOE) can be calculated as:
[tex]MOE=z\cdot \sigma_M=1.96 \cdot 2=3.92[/tex]
Then, the lower and upper bounds of the confidence interval are:
[tex]LL=M-t \cdot s_M = 80-3.92=76.08\\\\UL=M+t \cdot s_M = 80+3.92=83.92[/tex]
The range that we expect the average classroom test score to fall 95% of the time is (76.08, 83.92).
c) We can calculate this by calculating the z-score of X=79.
[tex]z=\dfrac{X-\mu}{\sigma}=\dfrac{79-80}{2}=\dfrac{-1}{2}=-0.5[/tex]
Then, the probability of getting a average score of 79 or higher is:
[tex]P(X>79)=P(z>-0.5)=0.69146[/tex]
The approximate probability that a classroom will have an average test score of 79 or higher is 0.69.
d) If the sample is smaller, the standard error is bigger (as the square root of the sample size is in the denominator), so the spread of the probability distribution is more. This results then in a smaller probability for any range.
e) If the population standard deviation is smaller, the standard error for the sample (the classroom) become smaller too. This means that the values are more concentrated around the mean (less spread). This results in a higher probability for every range that include the mean.
Which of the following choices represents the expanded form of the number 38,072?
30,000 + 800 + 70 + 2
30,000 + 8,000 + 70 + 2
30,000 + 8,000 + 700 + 2
3,000 + 800 + 70 + 2
Answer:
The second one.
Step-by-step explanation:
The others don't add up to that number
Mariko is training for a race and now runs 6.5 miles in about 52 minutes. Write an equation to represent the number of minutes, n, she will take to run m miles at this rate.
Answer:
52+n=m
Step-by-step explanation:
Answer:
6.5 /52 m = n
Step-by-step explanation:
The rate is 6.5 miles / 52 minutes
We are going to run m miles in n minutes
m = 6.5 / 52 * n
We want to solve for n
Multiply each side by 52/ 6.5
6.5 /52 m = 6.5 / 52 * n * 6.5 / 52
6.5 /52 m = n
Find the area of the rectangle ABCD. I need both green and grey box please.
Answer:
180
Step-by-step explanation:
12x15=180
Pictures of students were asked how far they lived from my school that the table below shows the distance in miles which statement best compares the mean distance is for the two groups
Answer:
Group A (distance in miles) 1, 1.5, 3.03, 3.2, 2.8, 1.5, 1.8, 2.5, 2.2) Group B (distance in miles) 2, 2.5, 3.23, 1.3, 1.8, 2.4, 3, 1.5, 1.8)Therefore, the correct answer is A) It is equal for Group A and Group B.
Use the information in the illustration to find the distance from the boathouse to the cabin. Round your answer to the nearest yard.
Answer:
The distance from the boathouse to the cabin = 50 yd (nearest yard)
Step-by-step explanation:
The question is incomplete.
Question:
To find the distance from the
boathouse on shore to the cabin on the island, a surveyor measures from the boathouse to point X as shown. He then finds m∠X with an instrument called a transit. Use the surveyor’s
measurements to find the distance from the boathouse to the cabin.
Find attached the diagram of the question.
Solution:
Let the distance from the boathouse to the cabin = y
the distance from the boathouse to the point X = 30yard
Find attached the diagram for the solution.
From the diagram, the triangle is a right angled triangle
Opposite = y
Adjacent = 30yd
∠X = 59°
Using trigonometry (SohCahToa)
We would apply Toa since adjacent is given and we are looking for opposite
tan θ = opposite/adjacent
tan 59° = y/30
y = 30 tan 59
y = 30(1.6643)
y = 49.929
y = 50 yd (nearest yard)
The distance from the boathouse to the cabin = 50 yd (nearest yard)
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The square root of 4 is 2. Since 3 is less than 4, the square root of 3 would be just under 2.
The first graph would be correct.
help
The Columbian Exchange is the name given to the items shared between the New World and the Old World. Once European exploration began, items passed both ways. Which of the following explains the result this exchange had on many Native Americans living in North and South America?
A.
Native Americans began using tobacco.
B.
Native Americans died because of diseases.
C.
Native Americans gave livestock to Europe.
D.
Native Americans started growing corn.
Answer:
A
Step-by-step explanation:
Dr. Gonzalez is considering joining the Garden Club. If he pays a $25 membership fee, he
can buy rosebushes from the club at a reduced price of $10 each. If he does not join the
club, he can buy rosebushes from a local nursery for $15 each. The graph below compares
the cost of buying rosebushes from the Garden Club and from the local nursery.
Answer:
In the Garden Club the cost will be a fixed fee of $25 and $10 for each rosebush, so if he buys X rosebushes, the total cost will be:
C1(X) = $25 + $10*X
While in the local nursery there is no initial cost, and each rosebush costs $15, so if he buys X rosebushes, the total cost will be:
C2(X) = $15*X
Now, let's find the value of X where C1 and C2 are equal, this is:
$25 + $10*X = $15*X
$25 = $15*X - $10*X = $5*X
X = 25/5 = 5
This means that if he buys 5 rosebushes, he will pay the same amount in both places.
If he buys less than 5 rosebushes, he will pay less in the local nursery (as it has a bigger slope, but no initial fee)
If he buys more than 5 rosebushes, he will pay less in the Garden club (because it has a smaller slope)
find the perimeter of a circle whose diameter is 7 cm
Find the perimeter of the circle is the same as finding the circumference of the circle.
Circumference Formula: C = 2πr
Divide the diameter by 2 to find the radius.
7 / 2 = 3.5
Solve using the given values.
C = 2(3.14)(3.5)
C = 2(10.99)
C = 21.98
Therefore, the circumference (perimeter) of the circle is 21.98cm²
Best of Luck!
plss help find how much paint will be needed to paint the jewelry box?
Answer:
135
Step-by-step explanation:
volume = width*length*height
5*9*3=135
we need 135inches³ to paint it
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Choose the answer based on the most efficient method as presented in the lesson.
If the first step in the solution of the equation -x + 6 = 5 - 3x is "subtract 5," then what should the next step be?
add x
add 3x
subtract 6
Answer:
add x
Step-by-step explanation:
get the constants on one side, and the variables on the other for easiest solving.
if I paid 38 dollars for 2800 apples how much would one cost me
Answer:
Step-by-step explanation:
Answer:
$73.68
Step-by-step explanation:
2800 divide by 38 equals 73.68
week. After 5 weeks the account holds $170. Write an equation that represents the amount y
(in dollars) of money in the account after x
weeks.
What are the solutions of this quadratic equation? 4x^2 + 3 = 4x + 2
Answer:
The answer is ±0.5 or ±1/2
Step-by-step explanation:
When you solve by using the quadratic formula, you get double roots that will solve the equation. Hope this helps!!
The solution of the quadratic equation is 1/2 and 1/2.
We have to find, the solution of the quadratic equation is [tex]4x^2 + 3 = 4x + 2[/tex].
To determine the solution of the quadratic equation following all the steps given below.
Equation; [tex]4x^2 + 3 = 4x + 2[/tex]
Step1; The equation is written in the standard form of the quadratic equation.[tex]4x^2 + 3 = 4x + 2\\\\4x^2 + 3 - 4x - 2=0\\\\4x^2 -4x +1 =0[/tex]
Step2; Factorize the equation for finding the solution of the equation,[tex]\rm 4x^2-4x +1 = 0\\\\4x^2-2x -2x + 1= 0\\\\2x(2x-1) - 1 (2x-1)=0\\\\(2x-1) ( 2x-1) = 0[/tex]
Step3; The solution for the equation is,[tex]\rm 2x- 1= 0 , \ 2x = 1 , \ x = \dfrac{1}{2}\\\\And \ 2x- 1= 0 , \ 2x = 1 , \ x = \dfrac{1}{2}\\\\[/tex]
Hence, The required solution of the equation is 1/2 and 1/2.
For more details refer to the link given below.
https://brainly.com/question/19776811
Help me pleaseeeeeee
I need help
Answer:
48
Step-by-step explanation:
In similar polygons, every side of one polygon is a certain number of times bigger than the corresponding side of the other polygon. This number is the scale factor. Since the perimeter of each polygon is the sum of the lengths of the sides of that polygon, the perimeters also have the same scale factor that the sides do.
For example, if a triangle has 3 sides measuring 5 cm each and a similar triangle has 3 sides measuring 10 cm each, you see that each side of the second triangle is 2 times the length of the corresponding side of the first triangle. The scale factor from the smaller triangle to the larger triangle is 2. Now look at the perimeters. Since 5 + 5 + 5 = 15 and 10 + 10 + 10 = 30, the perimeters are 15 cm and 30 cm, and again, the perimeter of the second triangle is the same 2 times bigger than the perimeter of the first triangle.
Now look at your problem.
The perimeter of the smaller flag to the right is 16.
We see a side on the larger flag is 15, but we don't see the same side length on the smaller flag, so 15 does not help us.
Now we see that a side of the smaller flag measures 4 and the corresponding side of the larger flag measures 12. We divide the larger side length by the corresponding smaller side length to find the scale factor.
12/4 = 3
The scale factor from the smaller flag to the larger flag is 3. The perimeters also have the same scale factor of 3.
perimeter = 3 * 16 = 48
Answer: 48
Answer:
48
Step-by-step explanation:
Similar polygons have their sides in proportion, and we call the proportion between pairs of corresponding sides on two similar polygons the scale factor between them. We want to find the perimeter of the larger flag given the smaller one, and comparing the side with length 12 on the larger one with the side of length 4 on the smaller, we get a scale factor of 12 / 4 = 3.
This tells us that all the lengths on the larger flag are 3 times longer than the corresponding lengths on the smaller flag. What happens to the perimeter when we scale all of the lengths? Well, if every side gets multiplied by three, the sum of those sides will naturally be multiplied by 3, too.
Our large flag has a perimeter 3 times bigger than the smaller one, then, and 3 × 16 = 48.
Can anyone help with these three questions will give 25 points
Answer:
Step-by-step explanation:
1). y + 2x < 6
(y + 2x) - 2x < 6 - 2x
y < -2x + 6 [Slope intercept form of the inequality]
2). y + 2x < 6
Since there is no sign of equal to (=) in the given inequality therefore, line graphed will be dashed.
Notation of less than (<) denotes the area down the line.
Option (4) will be the answer.
3). y + 2x < 6
x ≤ 2
Please find the graph attached.
A major home improvement store conducted its biggest brand recognition campaign in the company's history. A series of new television advertisements featuring well-known entertainers and sports figures was launched. A key metric for the success of television advertisements is the proportion of viewers who "like the ads a lot." A study of 1,189 adults who viewed the ads reported that 230 indicated that they "like the ads a lot." The percentage of a typical television advertisement receiving the "like the ads a lot" score is believed to be 22%. Company officials wanted to know if there is evidence that the series of television advertisements are less successful than the typical ad (i.e. if there is evidence that the population proportion of "like the ads a lot" for the company's ads is less than 0.22) at a 0.01 level of significance. 1) State H subscript 0 and H subscript 1. (2 points) 2) What critical value should the company officials use to determine the rejection region? (2 points) 3) What is the value of the test statistic? (4 points) 4) What is the conclusion of the hypothesis test? Is there evidence that the population proportion of "like the ads a lot" for the company's ads is less than 0.22?
Answer:
Step-by-step explanation:
Identify: Hypothesized π = 0.22 n =1189 X = 230
Estimate the sample proportion, p, of defective items. p= X/n = 230/1189 = 0.1934
List the formula for the standard error of a proportion. [tex]\sqrt{PQ/n}[/tex]
Estimate the standard error of a proportion. [tex]\sqrt{PQ/n} = \sqrt{0.22\times 0.78/1189} = 0.0120[/tex]
State the null and alternative hypotheses below.
H0: P = 0.22
H1: P<0.22
Illustrate the acceptance and rejection regions of the diagram to the right.
check the attached image below for the diagram
Identify the critical Z , -1.645
Fornulate the decision rule and list below.
If Z calculated is less than Z critical we reject null hypothesis
Calculate your test statistic.
[tex]Z= \frac{p-P}{\sqrt{PQ/n}} = \frac{0.1934-0.22}{0.0120}= -2.217[/tex]
Do you accept or reject the null hypothesis at 0.05 level of significance? Reject
State your conclusion. Should the quality control manage accept the shipment or return it?
WE have sufficient evidence that the population proportion of "like the ads a lot" for the company's ads is less than 0.22 at a 0.05 level of significance.
If a 0.01 level of significance had been used in the test, would you have accepted or rejected the null hypothesis?
at 0.01 level of significance the critical value of Z is -2.33
Since Z calculated is greater than Z critical value we accept the null hypothesis
turn to passive voice the child chose the hat
Answer:
The hat was chosen was the child.
Step-by-step explanation:
Match the following items by evaluating the expression for x = -3.
Answer:
1/9-1/31-39Step-by-step explanation:
x^-2 = (-3)^-2 = 1/(-3)^2 = 1/9
Each of the following is the previous value multiplied by -3,
x^-1 = x(x^-2) = (-3)(1/9) = -1/3
x^0 = x(x^-1) = (-3)(-1/3) = 1
x^1 = -3(1) = -3
x^2 = -3(-3) = 9
Arionna claims that since there are 3 feet in a yard, there are 9 cubic feet in a cubic yard. Which statement about her claim is true?
a.)Arionna is correct because there are 3 feet across the length of a cubic yard and 3 feet across the depth of a cubic yard. 3 times 3 = 9
b.)Arionna is correct because there are 3 feet in a yard and there are 3 dimensions in a cubic yard: length, depth, and height. 3 times 3 = 9
c.)Arionna is incorrect. There are only 3 cubic feet in a cubic yard because there are 3 feet in a yard, and the proportion will remain constant.
d.) Arionna is incorrect. There are 27 cubic feet in a cubic yard because a cubic yard is a prism with dimensions 3 ft Times 3 ft Times 3 ft. A prism with those dimensions will take 27 cubes to fill it if each cube is a unit cube of 1 ft.
Answer:
d.) Arionna is incorrect. There are 27 cubic feet in a cubic yard because a cubic yard is a prism with dimensions 3 ft times 3 ft times 3 ft. A prism with those dimensions will take 27 cubes to fill it, if each cube is a unit cube of 1 ft³.
Step-by-step explanation:
There are (3 ft)(3 ft) = 9 ft² in one square yard. To find the volume of a cubic yard, you need to multiply that by 3 ft again: (9 ft²)(3 ft) = 27 ft³.
_____
Additional comment
For many problems involving units, I like to keep the units with the numbers. That helps ensure the math is done correctly. In this problem, simply multiplying ft by ft gives ft^2, not ft^3, so you know right away that you haven't computed volume correctly.
What is the relationship between the diameter and radius?
Answer:
A
Step-by-step explanation:
pls mark me brainliest
the perimeter of a rectangle is 20 units. The length of the rectangle is the distance from(-2,6) to (5,6) What is the width in units of the rectangles?
Answer:
3 units.
Step-by-step explanation:
We can calculate the length, since it only moves on the "x" axis, since on the "y" axis, it remains the same.
We know that between -2 to 5, there are 7 units. 2 + 5 = 7.
Therefore this would be the length.
We know that the perimeter is equal to:
p = 2 * w + 2 * l
P = 20
20 = 2 * w + 2 * 7
2 * w = 20 - 14
w = 6/2
w = 3
therefore, the width value is 3 units.
Answer:
3
Step-by-step explanation:
Determine whether the set of vectors is orthonormal. If the set is only orthogonal, normalize the vectors to produce an orthonormal set.Bold u 1 equals [Start 3 By 1 Matrix 1st Row 1st Column one third 2nd Row 1st Column one third 3rd Row 1st Column one third EndMatrix ]and Bold u 2 equals [Start 3 By 1 Matrix 1st Row 1st Column negative one half 2nd Row 1st Column 0 Subscript font size decreased by 6 Superscript font size decreased by 6 3rd Row 1st Column one half EndMatrix ]
Answer:
(i) See attached image file
(ii) Option A
Step-by-step explanation:
See attached image file
Convert 475 milliliter to liters.
0.475
1000 milliliters is equal to 1 liter
Answer: 0.475 Liters
Step-by-step explanation: So, we know one liter is exactly 1,000 milliliters...therefore this would have to be a decimal.
Therefore, 475 milliliters to liters would be 0.475 liters.
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Answer:
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Step-by-step explanation:
The local supermarket buys lettuce each day to ensure really fresh produce. Each morning any lettuce that is left from the previous day is sold to a dealer that resells it to farmers who use it to feed their animals. This week the supermarket can buy fresh lettuce for $4.00 a box. The lettuce is sold for $10.00 a box and the dealer that sells old lettuce is willing to pay $1.50 a box. Past history says that tomorrow's demand for lettuce averages 250 boxes with a standard deviation of 34 boxes. Required: How many boxes of lettuce should the supermarket purchase tomorrow
Given Information:
Cost price = $4
Selling price = $10
Salvage value = $1.50
Average demand = μ = 250 boxes
Standard deviation = σ = 34 boxes
Required Information:
Number of lettuce boxes = ?
Answer:
The supermarket should purchase 268 boxes of lettuce
Step-by-step explanation:
The required number of lettuce boxes that supermarket should purchase is given by
Number of lettuce boxes = μ + (z*σ)
Where μ is the average demand of lettuce boxes, σ is the standard deviation, and z is the z-score which is given by
p = C_us/(C_us + C_os)
The z-score corresponding to probability p will be obtained.
The cost of under stocking is given by
C_us = Selling price - Cost price
C_us = $10 - $4
C_us = $6
The cost of over stocking is given by
C_os = Cost price - Salvage value
C_os = $4 - $1.50
C_os = $2.50
p = C_us/(C_us + C_os)
p = 6/(6 + 2.50)
p = 0.7058
p = 70.58%
The z-score corresponding to 70.58% probability is approximately 0.54
Number of lettuce boxes = μ + (z*σ)
Number of lettuce boxes = 250 + (0.54*34)
Number of lettuce boxes = 250 + (18.36)
Number of lettuce boxes = 268.36
Number of lettuce boxes ≈ 268
Therefore, the supermarket should purchase 268 boxes of lettuce.
How to use z-table?
Step 1:
In the z-table, find the probability you are looking for and note down the two-digit number of the given row. (e.g 0.5, 2.2, 0.5 etc.)
Step 2:
Then look up at the top of z-table and note down the value in the column for the remaining decimal point in the range of 0.00 to 0.09.
Step 3:
Finally, add the numbers obtained from step 1 and step 2.
2 cars departed the same place at the same
time. They traveled the same direction. One
traveled 50 mph for 4 hours. The other car
traveled 60 mph for 8 hours. How many miles
farther did the 2nd car travel?
Autism and Maternal Antidepressant Use A recent study41 compared 298 children with Autism Spectrum Disorder to 1507 randomly selected con- trol children without the disorder. Of the children with autism, 20 of the mothers had used antidepres- sant drugs during the year before pregnancy or the first trimester of pregnancy. Of the control children, 50 of the mothers had used the drugs.
(a) Is there a significant association between prena- tal exposure to antidepressant medicine and the risk of autism? Test whether the results are sig- nificant at the 5% level.
(b) Can we conclude that prenatal exposure to antidepressant medicine increases the risk of autism in the child? Why or why not?
Answer:
(a) We conclude that there is a significant association between prenatal exposure to antidepressant medicine and the risk of autism at 5% significance level.
(b) Yes, we can conclude that prenatal exposure to antidepressant medicine increases the risk of autism in the child.
Step-by-step explanation:
We are given that Autism and Maternal Antidepressant Use A recent study 41 compared 298 children with Autism Spectrum Disorder to 1507 randomly selected control children without the disorder.
Of the children with autism, 20 of the mothers had used antidepressant drugs. Of the control children, 50 of the mothers had used the drugs.
Let [tex]p_1[/tex] = proportion of mothers who had used drugs having Autism Spectrum Disorder in their children.
[tex]p_2[/tex] = proportion of mothers who had used drugs not having Autism Spectrum Disorder in their children.
(a) Null Hypothesis, [tex]H_0[/tex] : [tex]p_1=p_2[/tex] {means that there is no significant association between prenatal exposure to antidepressant medicine and the risk of autism}
Alternate Hypothesis, [tex]H_A[/tex] : [tex]p_1\neq p_2[/tex] {means that there is a significant association between prenatal exposure to antidepressant medicine and the risk of autism}
The test statistics that would be used here Two-sample z test for proportions;
T.S. = [tex]\frac{(\hat p_1-\hat p_2)-(p_1-p_2)}{\sqrt{\frac{\hat p_1(1-\hat p_1)}{n_1}+\frac{\hat p_2(1-\hat p_2)}{n_2} } }[/tex] ~ N(0,1)
where, [tex]\hat p_1[/tex] = sample proportion of mothers who had used drugs having Autism Spectrum Disorder in their children = [tex]\frac{20}{298}[/tex] = 0.067
[tex]\hat p_2[/tex] = sample proportion of mothers who had used drugs not having Autism Spectrum Disorder in their children = [tex]\frac{50}{1507}[/tex] = 0.033
[tex]n_1[/tex] = sample of children with Autism Spectrum Disorder = 298
[tex]n_2[/tex] = sample of children without Autism Spectrum Disorder = 1507
So, the test statistics = [tex]\frac{(0.067-0.033)-(0)}{\sqrt{\frac{0.067(1-0.067)}{298}+\frac{0.033(1-0.033)}{1507} } }[/tex]
= 2.281
The value of z test statistics is 2.281.
Now, at 5% significance level the z table gives critical values of -1.96 and 1.96 for two-tailed test.
Since our test statistic doesn't lie within the range of critical values of z, so we have sufficient evidence to reject our null hypothesis as it will fall in the rejection region due to which we reject our null hypothesis.
Therefore, we conclude that there is a significant association between prenatal exposure to antidepressant medicine and the risk of autism.
(b) Yes, we can conclude that prenatal exposure to antidepressant medicine increases the risk of autism in the child because if we reconsider our hypothesis for one-tailed test in which the null hypothesis states that the prenatal exposure to antidepressant medicine does not increases the risk of autism in the child.
For this hypothesis also, our test statistics will be more than the critical value of z and due to which we reject our null hypothesis and conclude that prenatal exposure to antidepressant medicine increases the risk of autism.
When a radius intersects a chord of a circle at a right angle, what conclusion can be made?
The radius is bisected.
The chord is bisected.
The radius and the chord are congruent.
The radius is twice as long as the chord.
Answer:
The chord is bisected
Step-by-step explanation:
This problem seek our knowledge on the mensuration of flat shapes, a circle.The chord of a circle is a segment whose endpoints are on the circle. when a perpendicular bisector ( the radius) of any chord passes through the center of the chord at right angle to the chord, the chord is bisected into two. This is a way or could give us a good way to find the center of any circle.
kindly find attached a diagram for your reference
Answer:
B
Step-by-step explanation:
Joesph and molly each have coin collections. Joesph starts with 15 coins in his collection and adds 25 coins each month. Molly starts with 25 coins in her collection and adds 25 coins to each month. If Joseph and molly continue to collect this way, how many coins will each person have after 10 months?
Answer:
Joseph- 265 coins
molly- 275 coins