Suppose scores on exams in statistics are normally distributed with an unknown population mean and a population standard deviation of three points. A random sample of 36 scores is taken and gives a sample mean of 68. Find a 85 % confidence interval estimate for the population mean exam score. Explain what the confidence interval means​

Answers

Answer 1

this the answer of queastions

Suppose Scores On Exams In Statistics Are Normally Distributed With An Unknown Population Mean And A
Answer 2

Step-by-step explanation:

67.18,68.82

Let mu be the true population mean of statistics exam scores. We have a large random samples of n=36 scores with a sample mean of 68.we know that the population standard deviation is sigma=3.A pivotal quantity is 3^sqrt(36)=(3/6)=68(1/2) which is approximately normally distributed. Therefore the 85%confidence interval is 68-(1/2)(1.6449), 68+(1/2)(1.6449) i.e (67.18,68.82)


Related Questions


[tex] \frac{3x - 2}{7} - \frac{5x - 8}{4} = \frac{1}{14} [/tex]

Answers

Answer:

[tex]x=2[/tex]

Step-by-step explanation:

[tex]\frac{3x-2}{7}-\frac{5x-8}{4}=\frac{1}{14}[/tex]

In order to factor an integer, we need to divide it by the ascending sequence of primes 2, 3, 5.

The number of times that each prime divides the original integer becomes its exponent in the final result.

In here,  Prime number 2 to the power of 2 equals 4.

[tex]\frac{3x-2}{7}-\frac{5x-8}{2^{2} }=\frac{1}{14}[/tex]

First, We need to add fractions-

Rule:-

[tex]\frac{A}{B} +\frac{C}{D} =\frac{\frac{LCD}{B}+\frac{LCD}{D}C }{LCD}[/tex]

LCD = [tex]7 \cdot 2^{2}[/tex]

[tex]\frac{4(3x-2)+7(-(5x-8))}{7*2^{2} } =\frac{1}{14}[/tex]

[tex]x=2[/tex]

OAmalOHopeO

How many
Assume that the mean hecaht of soldiers is 166cm
with a standard deration of 8. cm.
soldeers in a regiment of 1000 would you expect to
be over 177 cm tall.

Answers

Answer:

85

Step-by-step explanation:

Given that :

Mean height , μ = 166

Standard deviation, σ = 8

Sample size, n = 1000

Using the Zscore formula :

Zscore = (x - μ) / σ

x = 177

Z = (177 - 166) / 8

Z = 1.375

P(Z > 1.375) = 0.084566(Area to the right of Z)

P(Z > 1.375) * n

0.084566 * 1000 = 84.566 = 85 soldiers

Rules for multiplying exponents

Answers

Answer and Step-by-step explanation:

When multiplying exponents:

- Product of Powers: When the base of the exponents are the same, and the bases are being multiplied to each other, the exponents are added together.

Example: [tex]a^x + a^y = a^{x+y}[/tex]

- Different bases Same Exponents: When the bases of the exponents are different, but the exponents are the same, the bases multiply together (within a parenthesis) with the exponent on the parenthesis.

Example: [tex]a^x*b^x = (a*b)^x[/tex]

- Quotient of Powers: When the base of the exponents are the same, and they are being divided by each other, the exponents will subtract from each other.

Example: [tex]\frac{a^x}{a^y}= a^{x-y}[/tex]

- Power of a Power: When a base has an exponent, and that entire term has and exponent, the exponents multiply together.

Example: [tex](a^x)^y = a^{x*y}[/tex]

- Power of a Product: The opposite of Different bases Same Exponents. Distribute the exponent onto the different bases.

Example: [tex](ab)^x = a^x*b^x[/tex]

- Power of a Quotient: The opposite of Quotient of Powers. Distribute the exponent to the dividing bases.

Example: [tex](\frac{a}{b} )^x = \frac{a^x}{b^x}[/tex]

- Zero Power: Any number raised to the 0 power equals 1.

Example: [tex]a^0 = 1\\999999^0=1[/tex]

- Negative Exponent: Any number raised by a negative number goes to the denominator of a fraction (if not already in the denominator), and vise versa (goes to the numerator if not already in the numerator).

Example: [tex]a^-2 = \frac{1}{a^2} \\\\\frac{1}{b^-3} = b^3[/tex]

- Power of One: Any number raised to the power of 1 is the same number.

Example: [tex]a^1 = a\\\\999^1 = 999[/tex]

I hope this helps!

#teamtrees #PAW (Plant And Water)

Cho A=( căn x -4x /1-4x -1) : (1+2x/1-4x -2căn x/ 2căn x -1 -1)

Answers

Answer:

0.85714285714286 x 100 = 85.7143%.

Step-by-step explanation:

Find two numbers nearest to 8888888 which are exactly divisible by 2915 explain step by step​

Answers

Answer: 88,87,835 and 88,90,750.
Step-by-step explanation: 88,87,835 =2915*3049 , 8890750 = 2915*3050.

in triangle JKL, angle JKL is a right angle, line KM is an altitude, JL=20, ML=4. Find KM

Answers

9514 1404 393

Answer:

  KM = 8

Step-by-step explanation:

The ratio of long side to short side is the same for all of the triangles in this geometry:

  KM/ML = JM/KM

  KM² = ML·JM = 4(20-4) = 64

  KM = √64 = 8

The length of KM is 8 units.

what is a cell and why it is necessary​

Answers

CELL

Cells are the basic building blocks of living things. The human body is composed of trillions of cells, all with their own specialised function. Cells are the basic structures of all living organisms.

IMPORTANCE

Cells provide structure for the body, take in nutrients from food and carry out important functions.

I HOPE THIS WILL HELP YOU IF NOT THEN SORRY

HAVE A GREAT DAY :)

1/6+4/18 in simplest form

Answers

Answer:

7/18

Step-by-step explanation:

1/6 x 3 = 3/18

3/18 + 4/18 = 7/18

Answer:

7/18

Step-by-step explanation:

Make the denominators the same!

You can turn 1/6 into 3/18 by multiplying the numerator and denominator by 3. Then you add the numerators of 3/18 and 4/18 together to get 7/18.

It can't be simplified any further :)

help please! I need the answer quickly! thank you!

Answers

Answer:

B) 1 unit to the left

Step-by-step explanation:

a word problem on proportions using a unit rate
Lashonda made $273 for 13 hours of work.
At the same rate, how many hours would she have to work to make $231?
hours
Х
?

Answers

eleven hours -  11 hours

She would have to work 11 hours to make $231.

Step 1: 273/13 = 21
So, x equals 21

Step 2: 231/21 = 11

Turn 43 1/23 into an improper fraction

Answers

Answer:

990/23

Step-by-step explanation:

Step 1

Multiply the denominator by the whole number

23 × 43 = 989

Step 2

Add the answer from Step 1 to the numerator

989 + 1 = 990

Step 3

Write answer from Step 2 over the denominator

990/23

I hope this answer helps you out! Brainliest would be appreciated.

When a sample has an even number of observations, the median is the

Group of answer choices

observation in the center of the data array

average of the two observations in the center of the data array

value of the most frequent observation

Answers

Answer:

average of the two observations in the center of the data array

Step-by-step explanation:

When there is an odd number, we use the middle

Example

1,5,9

The median is 5

When there is an even number

1,3,5,7

The middle is between the 3 and 5 so we average the middle number

(3+5)/2 = 4

Answer:

the answer is => observation in the center of the data array

Step-by-step explanation:

[tex]\sf{}[/tex]

guys pls tell me this answer as soon as possible​

Answers

que es un cuadrilatero

PLEASE HELP!! URGENT

Answers

Answer:

y=105

Step-by-step explanation:

82+75+x=180

157+x=180

x=23

82+23=y

105=y

Find the distance between the points (-4, -2) and (-8, 6)

Answers

Answer:

distance=√[(x2-x1)²+(y2-y1)²]

√[{6-(-2)}²+ (-8-(-4))²]

√(64+16)

√[100]

10

Points given

(-4,-2)(-8,-6)

Distance:-

[tex]\\ \sf \longmapsto \sqrt{(x_2-x_1)^2+(y_2-y_1)^2}[/tex]

[tex]\\ \sf \longmapsto \sqrt{(-8+4)^2+(6+2)^2}[/tex]

[tex]\\ \sf \longmapsto \sqrt{(-4)^2+(8)^2}[/tex]

[tex]\\ \sf \longmapsto \sqrt{64+16}[/tex]

[tex]\\ \sf \longmapsto \sqrt{80}[/tex]

[tex]\\ \sf \longmapsto 8.4[/tex]

Simplify the given expression.

Answers

Answer:

8x-21

----------------------

(2x-7)(2x+7)

Step-by-step explanation:

7                       4

-----------   + ------------

4x^2 -49    2x+7

Factor  ( notice that it is the difference of squares)

7                       4

-----------   + ------------

(2x)^2 - 7^2    2x+7

7                       4

-----------       + ------------

(2x-7)(2x+7)    2x+7

Get a common denominator

7                       4(2x-7)

-----------       + ------------

(2x-7)(2x+7)    (2x-7)(2x+7)

Combine

7 +4(2x-7)

----------------------

(2x-7)(2x+7)  

7 +8x-28

----------------------

(2x-7)(2x+7)  

8x-21

----------------------

(2x-7)(2x+7)  

Answer:

(8x - 21) / (2x + 7)(2x - 7)

Step-by-step explanation:

7 / (4x^2 - 49)+ 4 / (2x + 7)

= 7 / (2x + 7)(2x - 7) + 4 / (2x + 7)

LCM = (2x + 7)(2x - 7)   so we have

(7 + 4(2x - 7) / (2x + 7)(2x - 7)

=   (8x - 21) / (2x + 7)(2x - 7).

A sample of 375 college students were asked whether they prefer chocolate or vanilla ice cream. 210 of those surveyed said that they prefer vanilla ice cream. Calculate the sample proportion of students who prefer vanilla ice cream.

Answers

Answer:

The sample proportion of students who prefer vanilla ice cream is 0.56.

Step-by-step explanation:

Sample proportion of students who prefer vanilla ice cream:

Sample of 375 students.

Of those, 210 said they prefer vanilla ice cream.

The proportion is:

[tex]p = \frac{210}{375} = 0.56[/tex]

The sample proportion of students who prefer vanilla ice cream is 0.56.

How many unit cubes are on each layer of the cube?

6
3
12
9

Answers

Answer:

6

Step-by-step explanation:

Remember: Each layer has 6 cubes. Step 3 Count the cubes. cubes Multiply the base and the height to check your answer. So, the volume of Jorge's rectangular prism is cubic centimeters. if wrong very sorry

Answer:

9

Step-by-step explanation:

took the test

look at the image below

Answers

Answer:

SA = 153.9m^2

Step-by-step explanation:

SA = 4[tex]\pi[/tex][tex]r^{2}[/tex]

r = 3.5

SA = 4[tex]\pi[/tex][tex](3.5)^{2}[/tex]

SA = 4[tex]\pi[/tex](12.25)

SA = 49[tex]\pi[/tex]

SA = 153.9m^2

Tom and Jerry had a race. Tom started at 0200 running at 4.5km per hour. Jerry started
later at 6:30am running at 6.5km per hour. After five hours, who was ahead, and by how
much (answer in kilometres)

Answers

Answer:

Tom, 10.25

Step-by-step explanation:

Distance covered by Tom=4.5*(4 1/2+5)=81/4=42.75km

Distance covered by Jerry=6.5*(5)=32.5km

Tom is ahead from Jerry by 10.25km

Plzzz I’m giving a away 25 points

Answers

Answer:

sin ß = opposite / hypotenuse

sin45° = x / 4√2

Cross multiply

x = sin 45° × 4√2

x = √2/2 × 4√2

x = 4 × √2 ×√2 / 2

x = 4 × 2 / 2

x = 8 / 2

x = 4

Test scores are normally distributed with a mean of 68 and a standard deviation of 12. Find the z – score for a grade of 74. Round your answer to two numbers after the decimal.

Answers

Answer:

gang nem

Step-by-step explanation:

Find the value of x. Round to the nearest tenth.

Answers

Answer:

1.6 ft

Step-by-step explanation:

If you use the Pythagorean Theorem to solve for x, you get:

[tex]x=\sqrt{2.1^2-1.4^2}[/tex]

[tex]x=\sqrt{2.45} = 1.56524758425[/tex]

Rounded to the nearest tenth, the answer is 1.6

Jared works at a clothing store and is listening to a customer complain about a shirt he purchased that's damaged. Which behavior can Jared exhibit to show good communication skills with the customer? O a) Stopping the customer to quickly explain the store's return policy b) Repeating back what he has heard once the customer is done speaking Od Asking the customer how the shirt was damaged O d) Promising the customer a full refund even though it's against policy

Answers

Answer:

C

Step-by-step explanation:

in my point of view, my choice is C (asking the customer how the shirt was damaged) because when he finds out the reason why the shirt was damaged, he will explain whether or not that fault is in the store's return policy

another reason:

A) stopping the customers when they are talking, it's impolite behavior and i ensure that that customer will feel disatified.

B) i guess that customer doesnt waste of time because it

D) a full refund without finding the reason, i dont think it's a good idea

if 12 +2 =2 orderly what is 6 +3 orderly​

Answers

Answer:

3

Step-by-step explanation:

Please Mark me brainliest

Answer:

aren't one of the numbers in the equations supposed to be negative?

please help solve for y!

Answers

As both angles are supplementary

[tex]\\ \Large\sf\longmapsto 3x+(2x+3y)=180°[/tex]

[tex]\\ \Large\sf\longmapsto 3x+2x+3y=180[/tex]

[tex]\\ \Large\sf\longmapsto 5x+3y=180[/tex]

[tex]\\ \Large\sf\longmapsto 3y=180-5x[/tex]

[tex]\\ \Large\sf\longmapsto y=\dfrac{180-5x}{3}[/tex]

And

[tex]\\ \Large\sf\longmapsto 3x=90[/tex]

[tex]\\ \Large\sf\longmapsto x=\dfrac{90}{3}[/tex]

[tex]\\ \Large\sf\longmapsto x=30[/tex]

Now

Putting value

[tex]\\ \Large\sf\longmapsto y=\dfrac{180-5x}{3}[/tex]

[tex]\\ \Large\sf\longmapsto y=\dfrac{180-5(30)}{3}[/tex]

[tex]\\ \Large\sf\longmapsto y=\dfrac{180-150}{3}[/tex]

[tex]\\ \Large\sf\longmapsto y=\dfrac{30}{3}[/tex]

[tex]\\ \Large\sf\longmapsto y=10[/tex]

According to the graph of the rational function y equals 4 over the quantity x squared minus 4 end quantity which of the following statements is/are true? The function is even. The function is increasing for all values in the domain. There is a horizontal asymptote along the x-axis. I only I and II only I and III only I, II, and III

Answers

Using function concepts, it is found that the correct options are:

I and III only

--------------------------------

The function is:

[tex]y = \frac{4}{x^2 - 4}[/tex]

--------------------------------

Statement 1:

A function is even if: [tex]f(x) = f(-x)[/tex]

We have that:

[tex]f(x) = \frac{4}{x^2 - 4}[/tex]

[tex]f(-x) = \frac{4}{(-x)^2 - 4} = \frac{4}{x^2 - 4} = f(x)[/tex]

Since [tex]f(x) = f(-x)[/tex], the function is even, and the statement is true.

--------------------------------

Statement 2:

The function increases when: [tex]f^{\prime}(x) > 0[/tex]

The derivative is:

[tex]f^{\prime}(x) = \frac{-8x}{(x^2-4)^2}[/tex]

The denominator is always positive, but the numerator can be both positive/negative, which means that when the numerator is negative(x > 0), the derivative will be negative, thus the function will decrease and the statement is false.

--------------------------------

Statement 3:

A horizontal asymptote is given by:

[tex]y = \lim_{x \rightarrow \infty} f(x)[/tex]

In this question:

[tex]y = \lim_{x \rightarrow \infty} \frac{4}{x^2 - 4} = \frac{4}{\infty - 4} = \frac{4}{\infty} = 0[/tex]

y = 0 is the x-axis, thus, the statement is true, and the correct option is:

I and III only

A similar problem is given at https://brainly.com/question/23535769

Answer:

I and III

Step-by-step explanation:

Find two consecutive even numbers whose sum is 758.

Answers

Answer:

378 and 380

Step-by-step explanation:

The two even consecutive numbers that add up to 758 are going to be very close to half of 758. This is because two half of 758 are going to be the most similar addends of 758. This is important because the answers will be consecutive and therefore, must also be very similar. To solve, first, divide 758 by 2. This is 379, which is not an even number. So, to find the needed addends subtract and add 1 to 379. Both of these will be even and consecutive. These two numbers are 378 and 380. Then, to check you, can add them and see that they do sum 758.

Answer:

Step-by-step explanation:

Let the first number = x

Let the second number = x + 2

x + x + 2 = 758                      Collect like terms

2x + 2 = 758                         Subtract 2

2x = 758 - 2                          Combine

2x = 756                                Divide by 2

2x/2 = 756/2

x = 378

The first number is 378

The second number 380

If your teacher is really fussy, you can do it this way.

Let the first number = 2x

Let the second number = 2x + 2

The reason for this is to guarantee that both numbers were even to start with.

2x + 2x+2 = 758                    Combine like terms

4x + 2 = 758                          Subtract 2

4x = 756                                Divide by 4

x = 756/4

x = 189

Therefore 2x = 378

2x + 2 = 380                 Just as before.

A physical trainer decides to collect data to see if people are actually weight changing weight during the shelter in place. He believes there will not be a meaningful change in weight due to the shelter in place order. He randomly chooses a sample of 30 of his clients. From each client, he records their weight before the shelter in place order, and again 10 days after the order. A summary of the data is below.
The trainer claims, "on average, there is no difference in my clients' weights before and after the shelter in place order." Select the pair of hypotheses that are appropriate for testing this claim.
H0: µd = 0
H1: µd < 0 (claim)
H0: µd = 0 (claim)
H1: µd ≠ 0
H0: µd ≠ 0 (claim)
H1: µd = 0
H0: µd = 0 (claim)
H1: µd > 0
H0: µd = 0
H1: µd > 0 (claim)
H0: µd = 0
H1: µd ≠ 0 (claim)
H0: µd = 0 (claim)
H1: µd < 0
H0: µd ≠ 0
H1: µd = 0 (claim)
b) Select the choice that best describes the nature and direction of a hypothesis test for this claim.
This is a right-tail t-test for µd.
This is a right-tail z-test for µd.
This is a two-tail t-test for µd.
This is a two-tail z-test for µd.
This is a left-tail t-test for µd.
This is a left-tail z-test for µd.
c) Find the standardized test statistic for this hypothesis test. Round your answer to 2 decimal places.
d) Find the P-value for this hypothesis test. Round your answer to 4 decimal places.
e) Using your previous calculations, select the correct decision for this hypothesis test.
Fail to reject the alternative hypothesis.
Reject the alternative hypothesis.
Fail to reject the claim.
Reject the claim.
Fail to reject the null hypothesis.
Reject the null hypothesis.
f) Consider the following statements related to the trainer's claim. Interpret your decision in the context of the problem (ignoring the claim) and interpret them in the context of the claim.

Answers

Answer:

H0: µd = 0 (claim)

H1: µd ≠ 0

This is a two-tail t-test for µd

Step-by-step explanation:

This is a paired (dependent) sample test, with its hypothesis is written as :

H0: µd = 0

H1: µd ≠ 0

From the equality sign used in the hypothesis declaration, a not equal to ≠ sign in the alternative hypothesis is used for a two tailed t test

The data isn't attached, however bce the test statistic cannot be obtained. However, the test statistic formular for a paired sample is given as :

T = dbar / (Sd/√n)

dbar = mean of the difference ; Sd = standard deviation of the difference.

Find the value of x round to the nearest tenth.

Answers

9514 1404 393

Answer:

  117.9°

Step-by-step explanation:

Solving the Law of Cosines equation for C, we get ...

  C = arccos((a² +b² -c²)/(2ab))

Filling in the values from the figure, we find the angle X to be ...

  X = arccos((y² +z² -x²)/(2yz)) = arccos((55² +50² -90²)/(2·55·50))

  X = arccos(-2575/5500) ≈ 117.9°

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