From a sample of 45 students exam scores, it was found that there was a mean score was 75 and a standard deviation of 5. Assume the distribution of exam scores is normal.

construct and interpret a 95% confidence interval for the true mean score.

Answers

Answer 1

Answer:

The 95% confidence interval for the true mean score is [tex][73.539,76.461][/tex]

Step-by-step explanation:

Note that [tex]CI=\bar x\pm z\frac{s}{\sqrt{n}}[/tex] where [tex]\bar x[/tex] is the sample mean, [tex]z[/tex] is the upper critical value for the desired confidence level, [tex]s[/tex] is the sample standard deviation, and [tex]n[/tex] is the sample size.

Therefore, [tex]CI=75\pm 1.96\frac{5}{\sqrt{45}}\approx[73.539,76.461][/tex]


Related Questions

Please help me will give brainliest

Answers

Answer:

f(x) = 8.917x³ + 2x² + 0.083x - 7

Step-by-step explanation:

f(x)= y

Let the coefficients of x³, x², x be a, b, c and the constant be d

y= ax³ + bx² + cx + d

When y = -65, x = -2

-65= a(-2)³ + b(-2)² + c(-2) + d

-65= -8a + 4b - 2c + d ...eq. 1

When y = -14, x = -1

-14= a(-1)³ + b(-1)² + c(-1) + d

-14= -a + b - c + d ...eq. 2

When y = -7, x = 0

-7= a(0)³ + b(0)² + c(0) + d

-7 = d ...eq.3

When y = 4, x = 1

4= a(1)³ + b(1)² + c(1) + d

4= a + b + c + d ...eq. 4

when y = 78, x = 2

78 = a(2)³ + b(2)² + c(2) + d

78= 8a + 4b + 2c + d ...eq. 5

From eq. 3, d is - 7

putting d as - 7 in equations 1, 2, 4 and 5

In eq. 1,

-65= -8a + 4b - 2c - 7

-58= -8a + 4b - 2c ...eq. 6

In eq. 2

-14= -a + b - c - 7

-7= -a + b - c ...eq. 7

In eq. 4,

4= a + b + c - 7

11= a + b + c ...eq. 8

In eq. 5

78= 8a + 4b + 2c - 7

85= 8a + 4b + 2c ...eq.9

Subtracting eq. 9 from eq. 6

-143 = -16a - 4c... eq 10

subtracting eq. 8 from eq 7

-18= -2a - 2c

9= a + c

a = 9 - c ...eq 11

putting a as 9 - c in eq. 10

-143 = -16(9 - c) - 4c

-143 = -144 + 16c - 4c

1= 12c

c = 1/12 or 0.083

putting c as 1/12 in eq. 11

a = 9 - 1/12

a = 107/12 or 8.917

Putting a as 107/12 and c as 1/12 in eq. 8

11= 107/12 + b + 1/12

multiplying through by 13

132 = 107 + 12b + 1

132 - 108 = 12b

24= 12b

b = 24/12

= 2

Therefore, a= 8.917, b= 2, c= 0.083 and d = -7

f(x) = 8.917x³ + 2x² + 0.083x - 7

pls help. Have tried this problem a couple times but my answers didnt work

Answers

Answer:

infinite solutions...

Step-by-step explanation:

Is there more information to this problem? It can be pretty much anything.

N=3M

Nina can be 30 and Maryna 10, Nina can be 3 and Maryna 1, Nina can be 15 and Maryna 5...

Answer:

N - 4 = 3(M - 4). Simplified further, N - 4 = 3(M - 4)

Given,

Nina is N years old now and;

Maryna is M years old now

If four years ago, Nina was three times as old as Maryna was, then

Four years ago, Nina's age was N - 4

Four years ago, Maryna's age was M - 4

Given that Nina was three times as old as Maryna was four years ago, it means that

N - 4 = 3(M - 4)

To solve further

N = 3m - 12 + 4

N = 3M - 8

Step-by-step explanation:

If .60 = N could you write the expression .60N

Answers

Answer:

N+60

Step-by-step explanation:


Find the future value of $124,357 deposited at 8% compounded quarterly for 4 years

Answers

Answer:

Future value, $63,398.79; Interest, $16,798.79

Step-by-step explanation:

what number I am if I am a factor of 90 but not a multiple of 6 and 9 i am greater than 10 but smaller than 20​

Answers

Answer:

15

Step-by-step explanation:

15 can go into 90, 6 times. It is neither a multiple of 6 or 9. It is larger than 10 and smaller than 20.

state whether each of the following equations represent growth or decay.

Answers

Answer:

ehhh Pfouto math ni

dali raka AA yooo

Compare the quantities in Column A and Column B.
Column A
Column B
the y-intercept of the the y-intercept of the
line for the equation line for the equation
2y = 3x - 4
4x-2y=4
[A] The quantity in Column A is greater. [B] The quantity in Column B is greater.
[C] The quantities are equal.
[D] The relationship cannot be determined from the information given.

Answers

The y-intercept of [tex]2y = 3x - 4[/tex] and the y-intercept of [tex]4x - 2y=4[/tex] are equal

The equations are given as:

[tex]2y = 3x - 4[/tex]

[tex]4x - 2y=4[/tex]

Make y the subject in both equations

First equation

[tex]2y = 3x - 4[/tex]

[tex]y = \frac 32x - 2[/tex]

Second equation

[tex]4x - 2y=4[/tex]

[tex]y = 2x - 2[/tex]

A linear equation is represented as:

[tex]y = mx + b[/tex]

Where b represents the y-intercept

So: By comparison,

[tex]b_1 = 2[/tex] --- the y-intercept of the first equation

[tex]b_2 = 2[/tex] --- the y-intercept of the second equation

2 = 2.

Hence, the y-intercept of [tex]2y = 3x - 4[/tex] and the y-intercept of [tex]4x - 2y=4[/tex] are equal

Read more about y-intercepts at:

https://brainly.com/question/4015585

How do you use observed data to predict unobserved

Answers

You can determine that the test scores will drop with more hours of tv watched. Though as you can also notice there seem to be more outliers later in the data so you can determine that what is I observed will have more outliers than what is observed.

what is an equation of the line that passes through the points (2,-5) and (-3,-5)?

Answers

Answer:

y = -5

Step-by-step explanation:

yeah-ya....... right?

Answer:

Step-by-step explanation:

as both y values are -5, slope is zero and y intercept is -5

y = 0x - 5

y = -5

6. (5 points) Graph using two intercepts; show your work in finding the intercepts. 6x - 3y = 18
х

Answers

Answer:

Divide both sides by 18. The new coefficients will be the reciprocals of the intercepts:

[tex]6x-3y=18 \rightarrow \frac6{18}x - \frac3{18}y = 1 \rightarrow \frac x3-\frac y6 =1[/tex] The two intercepts are then 3 and -6.

(I know, dividing by 3 both sides of the equations would have made the whole process way easier).

Alternatively, plug x = 0 to find the y intercept and y=0 to find the x intercept. Either way the graph will look something like the one I'm sketching on paint.

[tex]5/4+3/4+1/4=[/tex]

Answers

5/4 + 3/4 + 1/4

=9/4

= 2 1/4

= 2.25

What is the slope of this graph?


a.4

b.−4

c.14

d.−14

Answers

Answer:

B

Step-by-step explanation:

just look at where the line crosses the coordinate plane

help please asappppppppp​

Answers

Answer:

First Equation: 6a-23

Second Equation: 5a-20

Step-by-step explanation:

So, I think you want me to answer part 2...

For the first equation, we can see that the denominator stays the exact same, meaning the numerator will also not change.

For the second equation, we can see the denominator changed from a-3 to 5a-15. The denominator was simply multiplied by 5. Since the denominator was multiplied by five we must multiply the numerator by five as well.

5(a-4)

5a-20

Hope this helps :)

A boat travels upstream a distance of 24 miles on a
river whose current is a constant rate of 3 mph. The boat returns downstream. The trip up the
river and back down the river takes a total time of 6 hours. What would the speed of the boat
be in still water?

Answers

Answer:the answer will be 48

Step-by-step explanation: 24 divided by 3 =8 x 6 =48

I REALLY HOPE THIS HELPS

NO LINKS!!

Which type of comic does not have vertices or foci? ​

Answers

Answer:

  b) Circle

Step-by-step explanation:

All of the conic sections have vertices and foci. These features are not usually talked about for a circle, so perhaps "circle" is the expected answer.

__

A circle is a special case of ellipse with eccentricity 0. Its foci are coincident at its center, and its vertices are the ends of any pair of perpendicular diameters.

Solve the following system of equations:

Answers

Answer:

The correct answer is option B: (-1, -1).

Step-by-step explanation:

The easiest way to solve this system is using elimination, or by adding the two equations together. We don't have to modify the equations at all, since the x's will already cancel out as written.

Upon addition, we get:

9y = -9

If we solve the equation by dividing both sides by 9, we get:

y = -1

To find the x value, we can substitute this value back into either of our original equations.

6x + 4y = -10

6x - 4 = -10

To solve for x, we should isolate the variable, or get it alone on one side of the equation.

6x = -6

x = -1

Therefore, the solution to the system of equations is x = -1 and y = -1, or (-1, -1), which is option B.

3x+5y−7x+6=12
Calculate.Solve for x.​

Answers

The value of x from the equation is x = (5y - 6)/4

Given the equation 3x+5y−7x+6=12

collect the like terms;

3x-7x + 5y + 6=12

-4x + 5y = 12 - 6

-4x + 5y = 6

Subtract 6 from both sides

-4x + 5y - 5y = 6 - 5y

-4x = 6 - 5y

4x = 5y - 6

x = (5y - 6)/4

Hnce the value of x from the equation is x = (5y - 6)/4

learn more on subject of formula here: https://brainly.com/question/657646

Simplify the product.
(16+13)(12-2)

Answers

Answer:

290

Step-by-step explanation:

(16+13)(12-2)= 29 * 10 = 290

Answer:

290

Step-by-step explanation:

(16+13)(12-2)

29*10

290

A total of 180 students and 35 chaperones are going on a field trip to the Smithsonian Institution in Washington, D. C.

Write the ratio in simplest form.


the ratio of students to people on the trip ​

Answers

Answer:

36 : 43

Step-by-step explanation:

So, we have 180 : 35 + 180 in the students to people on the trip180 : 21536 : 43Therefore, the ratio of students to people is 36 : 43

1) write the measurement 4009 mm into the place value table below

a) what is 4009 mm in cm
b) what is 4009 mm in m

2) how many millimeters is 6 liters​

Answers

Answer:

a)400.9 cm

b)4.009 m

c) 181.71 mm

Step-by-step explanation:

a) First know that when you move from cm to mm you multiply by 10 and when you move from mm to cm you divide by 10 because 1mm= 0.1 cm

so 4009mm/10 = 400.9cm

b) when you move from m to mm you multiply by 1000 but when you move from mm to m you divide by 1000 ,so 4009/1000 = 4.009

c) 1litre= 1000000mm³

6litre= x

xlitre= 6000000 litre mm³

divide by litre

x= 6000000 mm³

but according to the question we are not looking for cubic mm but mm the fore remove cubic by insterting cube root

x= 181.71 mm

: . c)181.71 mm

Which graph represents the function?

Answers

Answer:

I believe it's the middle graph. since their is a closed dot on the first line and the other 2 inequality symbols indicate that their are 2 open dots, I think the middle is correct

what are the subsets of set B =(a. b. c. d)? ​

Answers

Answer:

{},{a},{b},{c},{d},{a,b},{a,c},{a,d},{b,c},{b,d},{c,d},{a,b,c},{a,b,d},{a,c,d},{b,c,d},{a,b,c,d}

Step-by-step explanation:

Find the perimeter of the rectangle whose: length = 1m, breadth = 75cm


Pls all answer fast PLS

Answers

Length of the rectangle = 1 mBreadth of the rectangle = 75 cm = 0.75 mWe know, perimeter of a rectangle = 2(length + breadth)Therefore, perimeter of the rectangle= 2(1 + 0.75) m = 2(1.75) m = 3.5 m

Answer:

The perimeter of the rectangle is 3.5 m or 350 cm.

Hope you could get an idea from here.

Doubt clarification - use comment section.

Of 92 adults selected randomly from one town, 61 have health insurance. Find a 90% confidence interval for the true proportion of all adults in the town who have health insurance. Group of answer choices 0.582 < p < 0.744 0.548 < p < 0.778 0.536 < p < 0.790 0.566 < p < 0.760

Answers

A 90% confidence interval for the true proportion of all adults in the town who have health insurance is 0.582 < p < 0.744

The formula for calculating the confidence interval is expressed as;

[tex]CI=p \pm z \cdot\sqrt{\frac{P(1-p)}{n} }[/tex]

p is the proportion = 61/92 = 0.66n is the sample size = 92z is the z-score at 90% = 1.645

Substitute the given parameters into the formula to have:

[tex]CI=0.66 \pm 1.645 \cdot\sqrt{\frac{0.66(1-0.66)}{92} }\\CI=0.66 \pm 1.645 \cdot\sqrt{\frac{0.66(0.34)}{92} }\\CI =0.66\pm 1.645(0.0495)\\CI=0.66 \pm 0.0814\\CI = (0.582, 0.744)[/tex]

Hence a 90% confidence interval for the true proportion of all adults in the town who have health insurance is 0.582 < p < 0.744

Learn more on confidence interval here: https://brainly.com/question/15712887

Elise works for a company that provides short-term loans to working people
who promise to pay back the loan from their next paycheck. Elise works for a
A. payday lender
B. mortgage bank
C. title company
D. credit union

Answers

The answer to your question is "payday lender"

Elise works for a  payday lender.

What is loans?

A loan is when money is given to another party in exchange for repayment of the loan principal amount plus interest.

As, Elise works for a company that provides short-term loans to working people who promise to pay back the loan from their next paycheck.

So, the pay lender is an  organization that lends money to customers who must pay it back when they receive their next pay.

Hence, Elise works for a  payday lender.

Learn more about this concept here:

https://brainly.com/question/26106234

#SPJ2

Samantha is about to buy her first new vehicle. She knows the model that she wants but all of the vehicles
available at the dealer's showroom have accessories, like fancy wheel hubs, that she doesn't need or want.
Which of the following is likely to be true?

Answers

Answer:

Samantha wants a simple, starter car, or the extra accessories have a higher price than the one's without it.

In the multiplication sentence below, which number is the product?
9x 10 = 90
A. 9
B. 10
C. 90
SUBMIT

Answers

Answer:

  C.  90

Step-by-step explanation:

The numbers being multiplied are "factors." The result of multiplication is a "product." In this problem, the product is 90.

Distributive property to remove parentheses 4(3+w)

Answers

Answer:

12+4w

Step-by-step explanation:

Multiply 4 by both sides

Jamie is x years old. His friend Ana is the same age.
Enter an expression in the box to represent the sum of Jamie's and Ana's ages.

Answers

Answer:  2x

Explanation:

Each person is x years old. Adding those unknown ages gets us x+x = 2x

We can think of it like x being one box, so x+x represents having two boxes which shortens to 2x.

How many minutes does it take for the goose to fly 1 mile if it takes 6 minutes to fly 18 miles

Answers

Answer:

1/3 minutes

Step-by-step explanation:

We can write a ratio to solve

6 minutes          x minutes

----------------  = ------------------

18 miles                  1 mile

Using cross products

6 * 1 = 18 x

6 = 18x

Divide each side by 18

6/18 = 18x/18

1/3 = x

1/3 minutes

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