Answer:
a) The standard error is s = 0.071.
b) Yes, as both sample sizes are above 30.
Step-by-step explanation:
To solve this question, we need to understand the central limit theorem and subtraction of normal variables.
Central Limit Theorem
The Central Limit Theorem establishes that, for a normally distributed random variable X, with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].
For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.
For a proportion p in a sample of size n, the sampling distribution of the sample proportion will be approximately normal with mean [tex]\mu = p[/tex] and standard deviation [tex]s = \sqrt{\frac{p(1-p)}{n}}[/tex]
Subtraction between normal variables:
When two normal variables are subtracted, the mean is the difference of the means, while the standard deviation is the square root of the sum of the variances.
Samples of size 86 drawn from population A with proportion 0.43
This means that [tex]n = 86, p = 0.43[/tex]. So:
[tex]s_A = \sqrt{\frac{0.43*0.57}{86}} = 0.0534[/tex]
Samples of size 60 drawn from population B with proportion 0.15:
This means that [tex]n = 60, p = 0.15[/tex]. So:
[tex]s_B = \sqrt{\frac{0.15*0.85}{60}} = 0.0461[/tex]
(a) Find the standard error of the distribution of differences in sample proportions A - B Round your answer for the standard error to three decimal places. Standard error=
This is:
[tex]s = \sqrt{s_A^2 + s_B^2}[/tex]
[tex]s = \sqrt{(0.0534)^2 + (0.0461)^2}[/tex]
[tex]s = 0.071[/tex]
The standard error is s = 0.071.
(b) Are the sample sizes large enough for the Central Limit Theorem. Yes or No?
Yes, as both sample sizes are above 30.
What is the value of the expression 2x^2 + 3xy - 4y^2 when x = 2 and y = -4?
Answer:
-80
Step-by-step explanation:
2x^2 + 3xy - 4y^2
x = 2 | y = - 4
2(2)^2 + 3(2)(-4) - 4(-4)^2
2 * 4 + 3(2)(-4) - 4 * 16
8 - 24 - 64
-80
What is the length of side a? Round to the nearest tenth of an inch. Enter your answer in the box.
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Answer:
14.4
Step-by-step explanation:
The Pythagorean theorem tells you ...
7² +a² = 16²
a² = 256 -49
a = √207
a ≈ 14.4
Sima drinks 2.5 litres of water each day.
A full glass holds 125 mililitres of water.
How many full glasses of water does Sima drink each day?
Answer:
20 glasses a day
Step-by-step explanation:
2.5litres equals 2500millilitres
2500÷125=20
Question 20
A transformer has 500 turns in its primary coil and 200 in the secondary coil.
a) If an AC voltage of 220 V and frequency 50 Hz is established in the primary coil, find the voltage
and the frequency induced in the secondary coil. (2)
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Answer:
88 V50 HzStep-by-step explanation:
The secondary voltage is proportional to the primary voltage. The constant of proportionality is the ratio of secondary turns to primary turns.
The secondary voltage is ...
(200/500)(220 V) = 88 V
__
A transformer does not change the frequency.* The voltage in the secondary coil is still 50 Hz.
_____
* Most transformers are designed to operate as linear devices. It is possible to design a transformer (with special core material) that operates non-linearly, and/or that is "tuned" to a frequency other than the one exciting the primary. That is, the secondary voltage may be some harmonic of the primary voltage. This would be a relatively unusual application of a transformer, beyond the apparent scope of the question here.
The telephone company charges $25 for a service call, and $15 for every 15 minutes the service representative works on repairs. Write an equation you could use to find the total cost of a repair visit.
Answer:
C=$25+$15m
Step-by-step explanation:
C is Cost
m is 15 minutes
The price for a visit would be $25 + $15 times the amount of time they work on repairs.
The equation you could use to find the total cost of a repair visit is C=$25+$15m.
What is a linear equation?It is defined as the relation between two variables, if we plot the graph of the linear equation we will get a straight line.
If in the linear equation, one variable is present, then the equation is known as the linear equation in one variable.
It is given that:
The telephone company charges $25 for a service call, and $15 for every 15 minutes the service representative works on repairs.
Let C is Cost and m be 15 minutes
From the data given in the question:
C = 25 + 15m
Thus, the equation you could use to find the total cost of a repair visit is C=$25+$15m.
Learn more about the linear equation here:
brainly.com/question/11897796
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Q22. Solve the equation x – 25 = 25 and state which axiom do you use here.
Answer:
x=50
Step-by-step explanation:
The solution to the equation x – 25 = 25 is x = 50. The axiom used to solve the equation is the addition property of equality.
To solve the equation x - 25 = 25, we want to isolate the variable x to find its value.
Adding 25 to both sides of the equation, we get:
x - 25 + 25 = 25 + 25
Simplifying, we have:
x = 50
Therefore, the solution to the equation is x = 50.
In this case, the axiom used to solve the equation is the addition property of equality. According to this axiom, if two expressions are equal, adding the same value to both sides of the equation preserves the equality.
In the given equation, we add 25 to both sides of the equation to maintain equality and obtain the solution x = 50. The addition property of equality allows us to perform this operation and determine the value of x.
To learn more about axioms click on,
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Casandra wants to buy a dress. She had of the money. Her mom gave her $120.00 but she was still short of the cost of the dress. What is the price of the dress?
I dont think I can be answered with just the given info... is some of the q missing still?
Closest we can do with above is dress cost = 120+ c
In a class, three-fifths of 25 students are girls. What is the number of girls in the class?
Answer:
15
Step-by-step explanation:
3/5*25
Answer:
15 girls
Step-by-step explanation:
(3/5) x 25 = 15
NO LINKS OR ANSWERING QUESTIONS YOU DON'T KNOW. Please help me with #29 and 30.
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Answer:
29) 1/5
30) independent; 64/225 ≈ 0.284
Step-by-step explanation:
In general, a "spinner" is considered to be a (mathematically ideal) device that returns one of the values with which it is marked, with a probability according to the area of the sector in which the mark resides. Usually, sectors are presumed to have equal areas. The result of one spin is generally considered to be independent of the result from any other spin. In the real world, an operator familiar with a given spinner can often ensure that the results do not have equal probability and are not independent. We ignore that possibility in math problems.
__
29) Of the numbers 1 to 15, there are three numbers less than 4. The probability of spinning one of them is 3/15 = 1/5.
__
30a) We have defined our spinner so that the events are independent. (See above.)
30b) In the set of numbers 1 to 15, 8 are odd and 7 are even. The probability of getting an odd number on any spin is 8/15. Because the results of successive spins are independent, the probability of any given sequence is the product of the probabilities of the numbers in that sequence.
P(2 odd) = P(odd)×P(odd) = (8/15)(8/15) = 64/225 ≈ 0.284
You need to save $1,300 to go overseas in two years. You deposit $800 in a savings account today. The account earns 10% interest. You will make an additional deposit in one year. How much must you deposit in one year in order to have enough to go on the trip?
Answer:
The additional deposit to be made in one year should be $ 301.81.
Step-by-step explanation:
Given that I need to save $ 1,300 to go overseas in two years, and I deposit $ 800 in a savings account today, that earns 10% interest, and I will make an additional deposit in one year, to determine how much must I deposit in one year in order to have enough to go on the trip, the following calculation must be performed:
800 x 1.1 = 880
(880 + X) x 1.1 = 1300
1300 / 1.1 = 1,181.81
1,181.81 - 880 = X
301.81 = X
Therefore, the additional deposit to be made in one year should be $ 301.81.
6+t=1 pls help.............
6+T=1
Try T=-5
6+(-5) = 1
Correct, So...
T=-5
I got a 90% on my quiz. Thanks to everyone who helped me!
Also this is a really is question but I'm to lazy to do it. Can someone give me the answer to this? (Question in the picture)
Answer: The answer is A
Step-by-step explanation:
In the picture, model A shows 3 groups and in the 3 groups are 4 lines !
I'm bad explaining but I hope this helps .
please helpppp!!! it’s timed!!!! thank u for helping!!!!!
Answer:
10π in.
Step-by-step explanation:
circumference of a circle = 2πr
=2*π*5
=10π in.
can someone help me with this question
Is the answer to this question 13.5
Answer:
i think its 13
Step-by-step explanation:
you are supposed to measure the lowest point of the liquid.
AABC has been translated 5 units to the right, as shown in the diagram. What
is the length of AB?
A. 10
B. 6
C. 31
D. 15
What is the perimeter of a triangle with the side lengths 4 cm, 6 cm, and (3y-2) cm?
Answer:
Step-by-step explanation:
P = 4 + 6 + (3y - 2) Remove the brackets
P = 10 + 3y - 2 Combine
P = 8 + 3y
Note 3y must be less than 8. That's because 2 sides of any triangle must be larger than the 3rd side or else you don't have a triangle.
in the right triangle AB, mc=90, a=4, and sinA=1/2. what is the length of the hypotenuse?
Given:
In a right angle triangle ABC, [tex]m\angle C=90^\circ , a=4[/tex] and [tex]\sin A=\dfrac{1}{2}[/tex].
To find:
The length of the hypotenuse.
Solution:
It is given that [tex]m\angle C[/tex], so opposite side of this angle is the hypotenuse, i.e., c.
In a right angle triangle,
[tex]\sin \theta=\dfrac{Perpendicular}{Hypotenuse}[/tex]
In the given triangle,
[tex]\sin A=\dfrac{a}{c}[/tex]
Substituting the given values, we get
[tex]\dfrac{1}{2}=\dfrac{4}{c}[/tex]
By cross multiplication, we get
[tex]1\times c=4\times 2[/tex]
[tex]c=8[/tex]
Therefore, the length of the hypotenuse is 8 units.
The answer and how to find the answer
Answer:
x = 1.9
Step-by-step explanation:
Thanks to a theorem we can use this proportion
10.47 : 4.44 = 4.44 = x
x = (4.44^2)/10.47 = 1,882865 = 1.9
HELP MATH ANSWER QUESTION
Answer:
Last one.
Step-by-step explanation:
[tex]\sqrt{3}[/tex] is used in 30-60-90 triangles
[tex]\sqrt{2}[/tex] is used in 45-45-90 triangles
Base is x, leg is x[tex]\sqrt{3}[/tex], hypotenuse is 2x
Answer:
x = 20 ; y= 10√3
Step-by-step explanation:
30, 60 , 90 triangle ratio is
Side opposite to 30 is a
a = AC = 10
Side opposite to 60 is a[tex]\sqrt{3}[/tex]
AB = a[tex]\sqrt{3}[/tex] = 10√3
Side opposite to 90 is 2a
BC = 2a = 2* 10 = 20
In the expansion of (1/ax +2ax^2)^5 the coefficient of x is five. Find the value of the constant a.
Answer:
80x⁴
Step-by-step explanation:
[tex](\frac{1}{ax} + 2ax^2)^5 = 5C_0(\frac{1}{ax})^5(2ax^2)^0 + 5C_1(\frac{1}{ax})^4(2ax^2)^1 + 5C_2(\frac{1}{ax})^3 (2ax^2)^2[/tex]
[tex]+ 5C_3 (\frac{1}{ax})^2(2ax^2)^3 + 5C_4(\frac{1}{ax})^1(2ax^2)^4 + 5C_5(\frac{1}{ax})^0(2ax^2)^5[/tex]
[tex]5C_0(\frac{1}{ax})^5(2ax^2)^0 =1 \times (\frac{1}{ax})^5 \times 1 = \frac{1}{a^5x^5}\\\\5C_1(\frac{1}{ax})^4(2ax^2)^1 = 5 \times (\frac{1}{ax})^4 \times (2ax^2)^1 = 10 ax^2 \times \frac{1}{a^4x^4} = \frac{10}{a^3x^2}\\\\5C_2 (\frac{1}{ax})^3 (2ax^2)^2= 10 \times (\frac{1}{ax})^3 \times (2ax^2)^2 = 10 \times \frac{1}{a^3x^3} \times 4a^2x^4 = \frac{40x}{a}\\\\5C_3 (\frac{1}{ax})^2 (2ax^2)^3 = 10 \times (\frac{1}{ax})^2 \times (2ax^2)^3 = 10 \times \frac{1}{a^2x^2} \times 8a^3 x^6 = 80ax^4\\\\[/tex]
[tex]5C_4(\frac{1}{ax})^1(2ax^2)^4 = 5 \times \frac{1}{ax} \times 16a^4x^8 = 80a^3x^7\\\\5C_5(\frac{1}{ax})^0(2ax^2)^5 = 1 \times 1 \times 32a^5x^{10}[/tex]
The fourth term of the expansion has the constant a,
the coefficient of a is 80x⁴
. year or once a year Your reading material illustrates a typical example of what happens if you pay just the minimum monthly payment every month on a credit card balance. In this example, approximately how long will it take to pay off the original debt completely? a. b. 2 years 5 years 12 years The debt will never be completely repaid. C. d.
7[tex]\sqrt -9[/tex]
Answer:
= 21i
Step-by-step explanation:
√-9 = 3i
= 7 . 3i
Multiply the numbers: 7 . 3 = 21
= 21i
Hope this helps!
Kristin is saving up money to go on a trip around the world next year. In order to make enough to pay for her trip, Kristin has to work at least 260 days this year.
Which of the following inequalities represents Kristin's possible number of workdays, d
Answer:
A.
D needs to be equal or more to 260
Answer:
The correct option is A
Step-by-step explanation:
HELPP ASAP plzzz tyy!!!!
Answer:
The domain of a function is the input numbers that, when plugged into a function, the result is defined. In simple words, we can define the domain of a function as the possible values of x that will make an equation true.
The range of a function is defined as a set of solutions to the equation for a given input. In other words, the range is the output or y value of a function. There is only one range for a given function.
hope this helps!
Step-by-step explanation:
simplify into one fraction 8x/x-8 - 2/x-8
Answer:
- 2+8x/x
Step-by-step explanation:
See image below:)
FYI you can use the app photo math you just take a pic of the problem and it gives you the answer and explains the steps and it is free
Answer:
(8x-2) / (x-8)
Step-by-step explanation:
8x/x-8 - 2/x-8
Since the denominator is the same, we can add the numerators
(8x-2) / (x-8)
Write an equation of a line that passes through (3,2) and (-5,6).
Karl set out to Alaska on his truck. The amount of fuel remaining in the truck's tank (in liters) as a function of distance driven (in kilometers) is graphed.
What distance did Karl travel by the time he had 200 liters of fuel?
_____ kilometers
Answer:
500 kilometers
Step-by-step explanation:
The fuel (y) Karl has in his car is a function of the distance (x) Karl travelled. The amount of fuel (y) is dependent on the distance (x) Karl travelled.
On the y-axis, we have amount of fuel.
On the x-axis, we have distance travelled.
At the time Karl travelled when he had 200 liters of fuel (y) remaining in his car, he had travelled a distance (x) of 500 kilometers.
We know this by looking at the graph given. When x (distance) = 500, y (fuel) = 200.
If the set of values in the table represents points on a line, what is the value of a?
Answer:
3
Step-by-step explanation:
Answer:
7
Step-by-step explanation:
just did it
3
5
6) through: (-3, -3), perp. to y=-**-4
5
A) y = 2x + B) y=--x+ 2
*
3
C) y=-x+2 D) y=-x+ 2
5
3
Step-by-step explanation:
answer in the image above