Answer:
-57
Step-by-step explanation:
f(-8)=6(-8)-9
f(-8)=-48-9
f(-8)=-57
g The average midterm score of students in a certain course is 70 points. From the past experience it is known that the midterm scores in this course are Normally distributed. If 29 students are randomly selected and the standard deviation of their scores is found to be 13.15 points, find the probability that the average midterm score of these students is at most 75 points. (Round your final answer to 3 places after the decimal point).
Answer:
0.98 = 98% probability that the average midterm score of these students is at most 75 points.
Step-by-step explanation:
To solve this question, we need to understand the normal probability distribution and the central limit theorem.
Normal Probability Distribution:
Problems of normal distributions can be solved using the z-score formula.
In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.
Central Limit Theorem
The Central Limit Theorem estabilishes 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.
The average midterm score of students in a certain course is 70 points.
This means that [tex]\mu = 70[/tex]
29 students are randomly selected and the standard deviation of their scores is found to be 13.15 points.
This means that [tex]\sigma = 13.15, n = 29, s = \frac{13.15}{\sqrt{29}} = 2.44[/tex]
Find the probability that the average midterm score of these students is at most 75 points.
This is the pvalue of Z when X = 75. So
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
By the Central Limit Theorem
[tex]Z = \frac{X - \mu}{s}[/tex]
[tex]Z = \frac{75 - 70}{2.44}[/tex]
[tex]Z = 2.05[/tex]
[tex]Z = 2.05[/tex] has a pvalue of 0.98.
0.98 = 98% probability that the average midterm score of these students is at most 75 points.
Stuck On this one too. Think I’m missing a step
Answer:
The answer is B) 152
Step-by-step explanation:
Is this statement always true? Or sometimes true? Or
never true?
X-y is greater than x+y
Always
Sometimes or
Never
Answer:
Sometimes. Say x = 3 and y = 4. 3 + 4 = 7, 3 - 4 = -1. However, the subtraction problem can be greater than the addition if you add some negatives into the mix. Say x = 3 and y = -4. 3 + (-4) is the same as subtracting 4, which give you -1. However, when you subtract negative four, it's the same as adding four, which gives you seven.
What is the equation of the line in slope-intercept form?
Answer:
y = mx + b
Step-by-step explanation:
In an arithmetic sequence, the 30th term is 112, and the 72nd term is 280. What is the 58th term?
Answer: 224
Step-by-step explanation: Subtract the terms and term number to find the common difference, 168/42=4. 112-29×4=-4=first term. 57×4+-4=224!
A school band performed a concert on four different days. The band sold tickets and snacks each day of the concert for a fundraiser. The first table shows the numbers of tickets sold and the amounts of money collected from ticket sales. The second table shows the numbers of snacks sold and the amounts of money collected from snack sales. If each snack costs the same price, what is the price per snack?
Answer:
$1.25
Step-by-step explanation:
There is a lot of unnecessary extra information we can ignore here. Simply divide the amount collected on any given day by the number of snacks sold.
53.75 / 43 = $1.25
Double check via another day:
45 / 36 = $1.25 ~ yup!
The price per snack is $1.25.
What is an expression?An expression contains one or more terms with addition, subtraction, multiplication, and division.
We always combine the like terms in an expression when we simplify.
We also keep all the like terms on one side of the expression if we are dealing with two sides of an expression.
Example:
1 + 3x + 4y = 7 is an expression.
3 + 4 is an expression.
2 x 4 + 6 x 7 – 9 is an expression.
33 + 77 – 88 is an expression.
We have,
From the table,
We see that,
43 snacks = $53.75
This means,
1 snack = 53.75/43 = 1.25
Similarly,
36 snacks = 45
1 snack = 45/36 = 1.25
Thus,
The price per snack is $1.25.
Learn more about expressions here:
https://brainly.com/question/3118662
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Conrad paid $52.26 for a pair of shoes. Michelle paid $3.89 more for a pair of shoes than Conrad paid for his.
Answer:
$60.30
Step-by-step explanation:
Answer:
The answer is $52.26 this is a trick question if you were finding how much Michael pay it will be $56.15
brainliest?
write 36minutes,1hour 40 minutes in simplest form
Answer:
3/5 of an hour, 60 minutes, 2/3 of an hour
Step-by-step explanation:
A graduate student conducted a study of field mice in rural Kansas. The student obtained a sample of 100 field mice and recorded the weight, in grams, of each mouse. The mean and standard deviation of the recorded weights are 35 grams and 2.4 grams, respectively. After the measurements were taken, it was discovered that the scale was not calibrated correctly. The student adjusted the 100 measurements by subtracting 3 grams from each measurement. What are the values of the mean and standard deviation of the corrected measurements
Subtracting 3 from all measurements, it is found that:
The mean will decrease by 3.The standard deviation will remain constant.What are the mean and the standard deviation of a data-set?The mean of a data-set is given by the sum of all values in the data-set, divided by the number of values.The standard deviation of a data-set is given by the square root of the sum of the differences squared between each observation and the mean, divided by the number of values.From this, we have that:
When 3 is subtracted from all measures, the sum of all observations will be subtracted by 3 x 100 = 300, hence the mean will decrease by 3.The mean decreases by 3, as does each observation, hence the sum of the differences squared between each observation and the mean remains constant, as does the standard deviation.More can be learned about the standard deviation of a data-set at https://brainly.com/question/12180602
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What is the value of x?
Enter your answer in the box.
X =
Answer:
free
Step-by-step explanation:
Answer:
x = 3
Step-by-step explanation:
ok then, firstly, lets make line CB into y
sin45 / y = sin 90 / 6[tex]\sqrt{2}[/tex]
in other words, as sin 90 = 1
y / sin45 = 6[tex]\sqrt{2}[/tex]
y = sin 45 * 6[tex]\sqrt{2}[/tex] = 6 as sin 45 = root2/2, and root2 * root 2 = 2, so
6*2/2 = 6
we also know BCD is 30*, as angles in a tri add up to 180*
so, x/sin30 = 6/sin90 = 6
x/sin30 = 6
6*sin30 = x
x = 3 as sin 30 = 1/2
15% of 20 is ??? please helpp
Answer:
I believe it is 3
Step-by-step explanation:
Answer:
the answer is 3 brainlest plz
Step-by-step explanation:
the area of a circle is 9 pi m^2 what is the circumference in meters
Answer:
6pi meters
Step-by-step explanation:
The formula for area of a circle is
A = pi r^2
9 pi = pi r^2
Divide each side by pi
9 = r^2
Take the square root of each side
sqrt(9) = sqrt(r^2)
3 =r
Now we can find the circumference
C = 2 * pi *r
C = 2 * pi *3
C = 6pi meters
Answer:
6pi meters
Step-by-step explanation:
give the person above brainliest
have a good one!
Simplify:-(x+9)
Plz help
Answer:
-x-9
Step-by-step explanation:
-(x+9)
The "-" at the beginning can be rewritten as -1
=-1(x+9)
To distribute -1 into the parentheses, multiply each value inside by -1
=(-1)(x)+(-1)(9)
=(-x)+(-9)
= -x-9
I hope this helps!
Valeria operates an orange juice stand. On Monday, she used 4 1/2
Tuesday she used 3/4 as many oranges as on Monday. How many bags of oranges did Valeria use on
Tuesday?
Answer:
0.37
Step-by-step explanation:
pls help me for a second
Answer:
do you need Anything else? hope i helped u
You have 12 pieces of candy and you eat 50% of the pieces. How many pieces of candy did you eat? Enter ONLY the number for your answer. *
Answer:
BLDM
Step-by-step explanation:
Answer:
6 pieces of candy
Step-by-step explanation:
50% is a half (of 100%)
12 pieces of candy in 100% divide by 2
6 = 50%
s
31
T
114°
R
U
v
In the figure above, RT = TU. What is
the value of x ?
A) 72
B) 66
C) 64
D) 58
Answer:
c 64 is your answer im pretty sure
Select the correct answer.
Solve the exponential equation for x.
Answer:
r = -2
Step-by-step explanation:
Hope this helps :)
HELP!!!
Find an explicit rule for the nth term of the sequence.
-5, -30, -180, -1080, ...
Answer:
multiply by 6
Step-by-step explanation:
a) 3 -2.(x + 3) = -18
Answer:
3 -2x^2 -6x= -18
Step-by-step explanation:
that's what got
Can Someone please help me !!! ( you have to fill out the blanks )
Answer:
1. 5(a-6) = 5a-30
2. 2(3a-b) = 6a-2b
3. 5(-5x+3) = -25x+15
4. -(2c+3) = -2c-3
Both of their first step are correct (Show your calculations to explain)
x-9 = 5
x = 14
2x-18 = 10
2x = 28
x = 14
Step-by-step explanation:
All Above
Robin had twenty-five math problems and thirty-six science problems for homework. If she finished thirty-four of the problems at school, how many problems did she have to do for homework?
Answer:
27 problems are remaining to solve
Use Lagrange multipliers to find the volume of the largest rectangular box in the first octant with three faces in the coordinate planes and one vertex in the given plane. x 3y 4z
I assume the given plane has equation
x + 3y + 4z = d
for some constant d ≠ 0.
You want to maximize the function V(x, y, z) = xyz subject to the above constraint. The Lagrangian would be
L(x, y, z, λ) = xyz - λ (x + 3y + 4z - d)
Find its critical points:
∂L/∂x = yz - λ = 0
∂L/∂y = xz - 3λ = 0
∂L/∂z = xy - 4λ = 0
∂L/∂λ = x + 3y + 4z - d = 0
The first three equations tell you that λ = yz = xz/3 = xy/4. Then, for instance,
yz = xz/3 → 3yz - xz = z (3y - x) = 0 → z = 0 or 3y - x = 0
If z = 0, we get zero volume which is not useful. So 3y = x. Similarly, you would find x = 4z and 3y = 4z, so a critical point occurs when x = 3y = 4z.
In the fourth equation, we get upon substituting
x + 3y + 4z = 3x = d → x = d/3, y = d/9, z = d/12
Then the largest volume of this box would be
V(d/3, d/9, d/12) = d ³ / 324
If Matrix A is 4 x 4, and Matrix B is 4 x 3, what is the size of matrix AB? If AB is undefined, please state so.
Why do I have to learn all of this if I'm gonna be a Rockstar when I'm older? I'm not gonna sing about geometry. or use algebra to write a song...
A marketing research consultant for a hotel chain hypothesizes that men and women differ in their color preference for guest rooms. The consultant shows pictures of rooms decorated with three different color scheme to each person in a random sample of 110 men and to each person in a random sample of 90 women. The consultant asks each person to choose his or her favorite color scheme. A chi-square test for homogeneity of proportions will be used to test the consultant’s hypothesis. Assuming that the conditions for inference are met, which of the following statements is true for the test?
A. The null hypothesis for the test is that the proportion of each gender who prefer each color scheme is
B. The sample size is too small to detect a significant difference in a chi-square test for homogeneity of proportions
C. The test is not valid because the sample sizes are not equal
D. The more that men and women differ in their color preferences, the larger the chi-square statistic will be
E. The test would also be appropriate if 90 married couples had been used for the two samples.
Answer:
D. The more that men and women differ in their color preferences, the larger the chi-square statistic will be.
Step-by-step explanation:
Hypothesis testing is a statistical technique which is used to identify the conclusion regarding whether to accept or reject the statistical statement. There is alternative hypothesis statement again which null hypothesis is tested.
A foreign-car dealer with warehouses in New York and Baltimore receives orders from dealers in Philadelphia and Trenton. The dealer would to minimize the shipping cost. The dealer in Philadelphia needs 3 cars and the dealer in Trenton needs 8. The New York warehouse has 5 cars and the Baltimore warehouse has 9. The cost of shipping cars from Baltimore to Philadelphia is $120 per car, from Baltimore to Trenton $90 per car, from New York to Philadelphia $100 per car, and from New York to Trenton $70 per car. Let x be the number of cars shipped from Baltimore to Trenton, and y be the number of cars shipped from Baltimore to Philadelphia. 5. Write the six inequalities associated with this problem.
Answer:
[tex]x \ge 0[/tex]
[tex]y \ge 0[/tex]
[tex]x + y \le 9[/tex]
[tex]8 - x \ge 0[/tex]
[tex]3 - y \ge 0[/tex]
[tex](8 - x) + (3 - y) \le 6[/tex]
Step-by-step explanation:
Given
x = Cars from Baltimore to Trenton
y = Cars from Baltimore to Philadelphia
Required
Write out 6 inequalities
First, 0 or more cars must be shipped to both locations
So:
[tex]x \ge 0[/tex]
[tex]y \ge 0[/tex]
Considering the warehouse in Baltimore.
(1) The warehouse can not ship more than the number of car it has (9).
So:
[tex]x + y \le 9[/tex]
Considering the warehouse in New York.
(1) After shipping cars to Trenton and Philadelphia, the warehouse will have 0 or more cars.
So:
[tex]8 - x \ge 0[/tex] --- To Trenton
[tex]3 - y \ge 0[/tex] --- To Philadelphia
(2) The warehouse cannot send out more than 6.
So:
[tex](8 - x) + (3 - y) \le 6[/tex]
So, the inequalities are:
[tex]x \ge 0[/tex]
[tex]y \ge 0[/tex]
[tex]x + y \le 9[/tex]
[tex]8 - x \ge 0[/tex]
[tex]3 - y \ge 0[/tex]
[tex](8 - x) + (3 - y) \le 6[/tex]
Evaluate the expression (4÷1)2
What is the Y value of solution to the following system? (Substitution)
x=3y+4
3x-5y=8
(This is worth 10 points please help this is due in 15 minutes )
Daniel is making cupcakes for a school bake sale. He wants to make 120 cupcakes. So far he has made 65% of them. How many more cupcakes does he need to make?