A teacher administers a standardized math test to his class of 75 students. The mean score (out of 300 possible points) is 235. From previous studies, you know the population standard deviation is 28. Using the sample data given, calculate a 95% confidence interval for the population mean.

Answers

Answer 1

Answer:

(228.663 ; 241.337)

Step-by-step explanation:

Given that:

Mean (m) = 235

Standard deviation (s) = 28

α = 95%

Zcritical at 95% = 1.96

Sample size (n) = 75

The confidence interval of the population mean can be obtained using the relation :

Mean ± Error

Error = Zcritical * (s/sqrt(n))

Error = 1.96 * (28/sqrt(75))

Error = 1.96 * 3.2331615

Error = 6.33699654

Error = 6.337

Lower boundary = 235 - 6.337 = 228.663

Upper boundary = 235 + 6.337 = 241.337

(228.663 ; 241.337)


Related Questions

Which one of these formulas describes the following sequence?

1,5,12,22,35

Answers

We can find a formula for nth term of the given sequence as follows:

1, 5, 12, 22, 35

The 1st differences between terms:

4, 7, 10, 13

The 2nd differences :

3, 3, 3

Since it takes two rounds of differences to arrive at a constant difference between terms, the nth term will be a 2nd degree polynomial of the form: [tex]a n^2 + b n + c[/tex], where c is a constant. The coefficients a, b, and the constant c can be found.

We can form the following 3 equations with 3 unknowns a, b, c:

[tex]1 = a\cdot1^2 + b\cdot1 + c\\5 = \cdot2^2 + b\cdot2 + c\\12 = a\cdot3^2 + b\cdot3 + c[/tex]

Solving for a, b, c, we get:

a = 3/2, b = -1/2, c = 0

Therefore, the nth term of the given sequence is:

[tex]\boxed{ a_n = \dfrac{3}{2}n^2- \dfrac{1}{2} n}[/tex]

Consider the solution to the linear equation.


5 (x + 6) = 50. 5 x + 30 = 50. 5 x = 20. x = 4.


Which describes the inverse operations used after the distributive property?

addition then division

subtraction then division

multiplication then subtraction

division then addition




the answer is b

Answers

Well it technically won’t be be because it isn’t b

Answer:

the answer is b i think

Step-by-step explanation:

12345

Jessica completed 21 math problems In 14 minutes at this rate how many math problems could complete in 30 minutes

Answers

Answer

45

Explanation

What is my perfect crime? I break into Tiffany's at midnight. Do I go for the vault? No, I go for the chandelier. It's priceless. As I'm taking it down, a woman catches me. She tells me to stop. It's her father's business. She's Tiffany. I say no. We make love all night. In the morning, the cops come and I escape in one of their uniforms. I tell her to meet me in Mexico, but I go to Canada. I don't trust her. Besides, I like the cold. Thirty years later, I get a postcard. I have a son and he's the chief of police. This is where the story gets interesting. I tell Tiffany to meet me in Paris by the Trocadero. She's been waiting for me all these years. She's never taken another lover. I don't care. I don't show up. I go to Berlin. That's where I stashed the chandelier.

QUICK PLS HELP
Before attending a basketball course, a player found that 60% of his shots made a
score. After attending the course, the player claimed he had improved. In his next
game he tried 12 shots and scored in 10 of them. Assuming shots to be
independent, test his claim at the 10% level of significance

Answers

Answer:

Step-by-step explanation:

60% = 7.2/12

83% = 10/12

He improved by a supposed 23%

The following is an example of what type of sequence? 3, 11, 19, 27, 35...

A: Geometric
B: Ratio
C: Ratio
D: Difference ​

Answers

Answer:

You have a series that increases by 8 Therefore it Ar^n-1So its a geomtric sequence

Julie is training to be in the hot dog eating contest. Her daily goal is to be able eat twice the amount of hot dogs she ate the day before. Her ultimate goal is to be able to eat 128 hot dogs in one day. If she eats 2 hot dogs on the first day, how many days will it take for her to reach her goal

Answers

The answer is - 64

Because 2 ➗128 = 64

PLEASE MARK BRAINLIEST!!
It takes Julie 7 days.

Day 1 - 2 hot dogs
Day 2 - 4
Day 3 - 8
Day 4 - 16
Day 5 - 32
Day 6 - 64
Day 7 - 128

Determine the value of x and y

Answers

Answer:

x=65, y=60

Step-by-step explanation:

x=65--->corrosponding angles with the triangle

x+y+55=180--->linear pair

(65)+y+55=180

y=60

Answer:

x=65 y=60

Step-by-step explanation:

Well, divide the hypotenuse between two triangles added onto the square root of the divisions between Mars and Pluto and we can derive the positive neutrons of the seventeenth quadratic of the Einstein constant equation.

or, know that x=65 due to it being on a parallel line to it, then due to their being 360 degrees around a point, 65+65+55+55=240, 360-240=120, then divide that by two to get it at y.

Please help with all pleaseeeee.

Answers

Step-by-step explanation:

5. da^2

7×4^2

=7×16

=112

6.g(b+e)

=10(8+3)

=10×11

=110

7.a+b(f+g)

=4+8(9+10)

=4+8×19

=4+152

=156

8.a+b/3

=4+8/3

=12/3

=4

The ordered pair (1, -2) is a solution to the system of linear equations.

2x + y = 0

-x + 2y = 5

True
False

Answers

Answer:

False

Step-by-step explanation:

2x + y = 0

Try (1, -2)

2(1) + (-2) = 0

2 + (-2) = 0

0 = 0

The solution works on the first equation.

-x + 2y = 5

-(1) + 2(-2) = 5

-1 - 4 = 5

-5 = 5

The solution does not work in the second equation.

Answer: False

Please send me a answer ASAP please thank you

Answers

Answer:

The answer would be D.9

What’s the equation of “two more than a certain number is 15 less than the product of 7/8 and the number”

Answers

Answer:

2+x=15-7/8x

Step-by-step explanation:

Answer:

Step-by-step explanation: the answer is -136 because you have the follow the steps of pemdas

Mr.Johnson leaves on a trip planning to travel 24 mph

Answers

Ummm is this a full question?
In conclusion, she is very slow

12. What is the slope of line with the points (2,2) and (1,5)?

Answers

Answer:

- 3

Step-by-step explanation:

The slope of a line given two points can be found by using the formula

[tex]m = \frac{ y_2 - y _ 1}{x_ 2 - x_ 1} \\[/tex]

From the question we have

[tex]m = \frac{5 - 2}{1 - 2} = - \frac{3}{1} = - 3 \\ [/tex]

We have the final answer as

- 3

Hope this helps you

1.15x10^-5 in standard form

Answers

Step-by-step explanation:

= 1.15 / 10⁵

115/10000000

0.0000115

is the correct answer

PLZ HELP! WILL GIVE BRAINLIEST!! PLZ SOLVE QUICK!!

Find the value of x by filling in the blanks in the provided statement - reason solution.

I NEED THE WHOLE STATEMENT REASON CHART FILLED OUT!! THANK YOU SO MUCH IF YOU HELP!

Answers

Answer 1. mZUTV=m/

= 850

2. m/R+m/S+mc

3. 3x + 2x +

4. x=

Please help!! I’ll do what ever! find m<1, m<2, m<3, m<4, and m<5,

Answers

Answer:

1.)111

2.)69

3.)60

4.)60

5.)51

1. Angles in a triangle and on a straight line add to 180°
180-65-46=69°
180-69=111°
2. 180-111=69°
3. 180-142=38°
180-38-82=60°
4. Opposite angles are equal =60°
5. 180-69-60=51°

At the beginning of the month, there were 80 ounces of peanut butter in the pantry. Now, there is 13 OF the amount less than at the beginning. How many ounces of peanut butter are in the pantry now?


A. 23•80


B. 13•80


C. 80−13


D. (1+13)•80


BRAINLIEST!!

Answers

Answer:

well for me

Step-by-step explanation:

I think it's 80-13 because it reduced by a minus 13

The answer is C because if your reducing 13 you would be subtracting

A bracelet costs $39.59. It is marked down 25%.

What is the final price of the bracelet after it is marked down?


$9.90

$29.69

$35.49

$49.49

Answers

Answer:

$29.69

Step-by-step explanation:

Marked down 25% means it is now worth 75% of original value.

0.75*39.59 = $29.69

please give thanks by clicking the heart buton :) happy holidays

Answer:

$29.70

Step-by-step explanation:

$39.59 / 4 = 9.8975.  Round up to 9.90

$39.59 - $9.90 = $29.69

Please help me thank you

Answers

Answer:

90

Step-by-step explanation:

90

The property that says 2+3 is equivalent to 3+2​

Answers

Commutative property
remember: a + b = b = a

If VY = 27, VZ = 18, and VW=8, find WX.
X
w
Z Y

Answers

Answer:

X is the answer

Step-by-step explanation:

Answer:

x is the answer because it is

Which of the following is equal to 3.TE?

Answers

Your answer is 37( 32 in ur mom equal to 3-4

Help I’ll give brainliest I don’t know the answer it’s for a grade :/ help bruh

Answers

Answer:

D

Step-by-step explanation:

Hope this helps.   :)     :D

Answer:

the answer is d.) (1,9)

Step-by-step explanation:

Really hope this helps xx

McAllister et al. (2012) compared varsity football and hockey players with varsity athletes from noncontact sports to determine whether exposure to head impacts during one season have an effect on cognitive performance. In the study, tests of new learning performance were significantly poorer for the contact sport athletes compared to the noncontact sport athletes. The following table presents data similar to the results obtained in the study.
Noncontact Athletes:
10, 8, 7, 9, 13, 7, 6, 12
Contact Athletes:
7, 4, 9, 3, 7, 6, 10, 2
a. Are the test scores significantly lower for the contact sport athletes than for the noncontact athletes? Use a one-tailed test with \alpha=.05
t-critical=
t=
b. Compute the value of (percentage of variance accounted for) for these data.
r^2= a. 0.123, b. 0.239, c. 0.138, d. 0.264

Answers

Answer:

[tex]t _{critical} = 1.760[/tex]

t = 2.2450

d. 0.264

Step-by-step explanation:

The null hypothesis is:

[tex]H_o: \mu_1 - \mu_2 = 0[/tex]

Alternative hypothesis;

[tex]H_a : \mu_1 - \mu_2 > 0\\[/tex]

The pooled variance t-Test would have been determined if the population variance are the same.

[tex]S_p^2 = \dfrac{(n_1-1)S_1^2+(n_2-1)S^2_2}{(n_1-1)+(n_2-1)}[/tex]

[tex]S_p^2 = \dfrac{(8-1)2.507^2+(8-1)2.8282^2}{(8-1)+(8-1)}[/tex]

[tex]S_p^2 = 7.14[/tex]

The t-test statistics can be computed as:

[tex]t= \dfrac{(x_1-x_2)-(\mu_1 - \mu_2)}{\sqrt{Sp^2 ( \dfrac{1}{n} +\dfrac{1}{n_2})}}[/tex]

[tex]t= \dfrac{(9-6)-0}{\sqrt{7.14 ( \dfrac{1}{8} +\dfrac{1}{8})}}[/tex]

[tex]t= \dfrac{3}{1.336}[/tex]

t = 2.2450

Degree of freedom [tex]df = (n_1 -1) + ( n_2 +1 )[/tex]

df = (8-1)+(8-1)

df = 7 + 7

df = 14

At df = 14 and ∝ = 0.05;

[tex]t _{critical} = 1.760[/tex]

Decision Rule: To reject the null hypothesis if the t-test is greater than the critical value.

Conclusion: We reject [tex]H_o[/tex] and there is sufficient evidence to conclude that the test scores for contact address s less than Noncontact athletes.

To calculate r²

The percentage of the variance is;

[tex]r^2 = \dfrac{t^2}{t^2 + df}[/tex]

[tex]r^2 = \dfrac{2.2450^2}{2.2450^2 + 14}[/tex]

[tex]r^2 = \dfrac{5.040025}{5.040025+ 14}[/tex]

[tex]r^2 = 0.2647[/tex]

Select the tables that show a proportional relationship between x and y.

Answers

Answer:

The table in blue

Step-by-step explanation:

Proportions! Please help quick!

Answers

Answer:

1. 3/195, 5/325, 9/585, 10/650

2. 2/15, 3/22.50,  5/37.50, 8/60

Step-by-step explanation:

0.96 is 1/10 of what?

Answers

Answer:

0.96*10 is 9.6.

Step-by-step explanation:

a map has a scale of 1.5 inches = 9 miles. On the map, two towns are 4 inches apart. What is the distance, in miles between the two towns?

Answers

Answer:

36

Step-by-step explanation:

i multpliy 9x4=36

a flag measures 90
feet by 60 feet. What is the perimeter of
this flag?

Answers

300 feet you add 90 twice which gets you 180 and then add 60 twice which gets you 120 and 120 plus 180 is 300

Please help, will give brainliest. Evaluate each expression for the given value of the variable(s). And Explain, Please.


3d - 4

d = 1.2

Answers

Answer:

-0.4

Step-by-step explanation:

3d-4 where d=1.2

substitute 1.2 for d and solve

3(1.2)-4

3.6-4= -0.4

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