A head librarian for a large city is looking at the overdue fees per user system-wide to determine if the library should extend its lending period. The average library user has $19.67 in fees, with a standard deviation of $7.02. The data is normally distributed and a sample of 72 library users is selected at random from the population. Select the expected mean and standard deviation of the sampling distribution from the options below.

a. σi= $7.02
b. σi= $0.10
c. σ = $0.83
d. µi= $0.27
e. µi= $2.80

Answers

Answer 1

Answer:

mean of the sample μ₁ = $0.27

Standard deviation of the sample σ₁ = $0.83

Step-by-step explanation:

Step(i):-

given mean of the population 'μ' = $19.67

Mean of the sample

                            [tex]= \frac{mean}{n} = \frac{19.67}{72} = 0.27[/tex]

Mean of the sample  μ₁ = 0.27

Step(ii):-

Given standard deviation of the  population  (σ) =  $7.02

Standard deviation of sample

                             [tex]= \frac{mean}{\sqrt{n} } = \frac{7.02}{\sqrt{72} } = 0.827[/tex]

Standard deviation of sample = 0.827≅ 0.83

Final answer:-

mean of the sample μ₁ = $0.27

Standard deviation of the sample σ₁ = $0.83


Related Questions

Brainliest to whoever gets this correct Which of the following is equal to the rational expression when x ≠ -3? x^2-9/x+3

Answers

Answer:

  see below

Step-by-step explanation:

We presume you want to simplify ...

  [tex]\dfrac{x^2-9}{x+3}=\dfrac{(x-3)(x+3)}{x+3}=\boxed{x-3}[/tex]

__

The numerator is the difference of squares, so is factored accordingly. One of those factors cancels the denominator.

Rebecca is a real estate agent who would like to find evidence supporting the claim that the population mean market value of houses in the neighborhood where she works is greater than $250,000. To test the claim, she randomly selects 35 houses in the neighborhood and finds that the sample mean market value is $259,860 with a sample standard deviation of $24.922. The test statistic t for a hypothesis test of H0 : μ = 250.000 versus Ha : μ > 250.000 is t 2.34 , which has 34 degrees of freedom. If 0.01 A) Fail to reject the null hypothesis that the true population mean market value of houses in the neighborhood where Rebecca works is equal to $250,000.
B) Reject the null hypothesis that the true population mean market value of houses in the neighborhood where Rebecca works is equal to $250,000.
C) There is enough evidence at the α-: 0.05 level of significance to support the claim that the true population mean market value of houses in the neighborhood where Rebecca works is greater than $250,000.
D) There is not enough evidence at the α-_ 0.05 level of significance to suggest that the true population mean market value of houses in the neighborhood where Rebecca works is not equal to $250,000.

Answers

Answer:

There is enough evidence at the α-: 0.05 level of significance to support the claim that the true population mean market value of houses in the neighborhood where Rebecca works is greater than $250,000.

Step-by-step explanation:

We are given that Rebecca randomly selects 35 houses in the neighborhood and finds that the sample mean market value is $259,860 with a sample standard deviation of $24.922.

Let [tex]\mu[/tex] = population mean market value of houses in the neighborhood.

So, Null Hypothesis, [tex]H_0[/tex] : [tex]\mu[/tex] = $250,000      {means that the population mean market value of houses in the neighborhood where she works is equal to $250,000}

Alternate Hypothesis, [tex]H_A[/tex] : [tex]\mu[/tex] > $250,000      {means that the population mean market value of houses in the neighborhood where she works is greater than $250,000}

The test statistics that would be used here One-sample t-test statistics because we don't know about population standard deviation;

                              T.S. =  [tex]\frac{\bar X-\mu}{\frac{s}{\sqrt{n} } }[/tex]  ~ [tex]t_n_-_1[/tex]

where, [tex]\bar X[/tex] = sample mean market value = $259,860

            s = sample standard deviation = $24,922

            n = sample of houses = 35

So, the test statistics  =  [tex]\frac{259,860-250,000}{\frac{24,922}{\sqrt{35} } }[/tex]  ~ [tex]t_3_4[/tex]

                                     =  2.34

The value of t-test statistic is 2.34.

Also, P-value of the test statistics is given by;

            P-value = P([tex]t_3_4[/tex] > 2.34) = 0.0137

            

Since our P-value is less than the level of significance as 0.0137 < 0.05, so we have sufficient evidence to reject our null hypothesis as it will fall in the rejection region due to which we reject our null hypothesis.

Therefore, we conclude that the population mean market value of houses in the neighborhood where she works is greater than $250,000.

how many nickels equal $18.45? (show your work)

Answers

Answer:

369

Step-by-step explanation:

One nickel = 0.05

0.05x=18.45

x=369

It take Donna 15 minutes to complete 3 levels of Candy Crush. At this rate, how many levels will she complete in 3 hours?​

Answers

Answer: she will have 36 levels completed

Solve for b. -11b+7 = 40 Two step equations

Answers

Step-by-step explanation:

-11b + 7 = 40

-11b = 40 - 7

-11b = 33

b = 33/-11

b = - 3

The answer to that will be -3

Find the value of x and the value of y.
A r= 15, y = 10/3
B. r=20, p=10/3
C. x=20/3, y = 513
D. r=15, y =53

Answers

Answer:

Step by step solution:

How do I solve 24-27?

Answers

Answer:

-3

Step-by-step explanation:

You find the difference between the numbers, which is 3. Then you make it negative since 24 is less than 27.

can 10/12 be simplified

Answers

Answer:

5/6

Step-by-step explanation:

10/12

Divide the top and bottom by 2

10/2 = 5

12/2 =6

the fraction becomes 5/6

Answer :

10/12

Reduce the fraction

= 5/6

Which fraction is equivalent to 2/-6? -2/6 2/6 -2/-6 6/2

Answers

Answer: -2/6 and -2/-6

Explanation: it doesn’t matter how many or where the negative signs are written on the fraction, it’s still negative.

The population of a community is known to increase at a rate proportional to the number of people present at time t. If an initial population P0 has doubled in 3 years, how long will it take to triple

Answers

It will take 7.925 years for the population to triple.

For the steps:

Teaching descriptive statistics. A study compared five different methods for teaching descriptive statistics. The five methods were traditional lecture and discussion, programmed textbook instruction, programmed text with lectures, computer instruction, and computer instruction with lectures. 45 students were randomly assigned, 9 to each method. After completing the course, students took a 1-hour exam.
a. What are the hypotheses for evaluating if the average test scores are different for the different teaching methods?
b. What are the degrees of freedom associated with the F-test for evaluating these hypotheses?
c. Suppose the p-value for this test is 0.0168. What is the conclusion?

Answers

Answer:

Step-by-step explanation:

a. The hypotheses are:

Null hypothesis: the average test scores are the same for the different teaching methods.

Alternative hypothesis: the average test scores are different for the different teaching methods.

b. To determine the degree of freedom for the F test: we must find two sources of variation such that we have two variances. The two sources of variation are: Factor (between groups) and the error (within groups) and add this up. Or use (N - 1). N is number in sample

c. With a p value of of 0.0168 and using a standard significance level of 0.05, we will reject the null hypothesis as 0.0168 is less than 0.05 and conclude that the average test scores are different for the different teaching methods.

by what rational number should we divide 22/7 so as to get the number -11/13?​

Answers

Answer:

7/54

Step-by-step explanation:

let thenumber be x

then 22/7 /x = -11/27  

= 22x/7 = -11/27

= x = -11*7/27*22 = 7/54

Hope it helps!!

this is a grade 4 maths question. i need help with doing a model from this question as well. thank you! —————————————————- a rope was cut into 2 pieces. The first piece was twice the length of the second piece. If the first piece was 5m 50cm long what was the length of the rope before it was cut

Answers

Answer:825cm

Step-by-step explanation:550cm/2=275cm

275*3=825cm

A File that is 242 megabytes is being downloaded.If the download is 12.9%complete,how many megabytes have been downloaded?Round your answer to the nearest tenth.

Answers

Answer:31

Step-by-step explanation: Since you are trying to find a percentage of a number all you have to do is multiply 242 by 12.9% and because you have to round to the nearest tenth it will be 31

Jalisa earned $71.25 today babysitting, which is $22.50 more than she earned babysitting yesterday. The equation d + 22.50 = 71.25 can be used to represent this situation, where d is the amount Jalisa earned babysitting yesterday. Which is an equivalent equation that can be used to find the amount Jalisa earned babysitting yesterday? 71.25 minus 22.50 = d 71.25 + 22.50 = d d + 71.25 = 22.50 d minus 22.50 = 71.25

Answers

Answer:

71.25 - 22.50 = d

Step-by-step explanation:

To find how much she earned yesterday, we subtract how much she earned today by the amount more she earned.

Answer:

A

Step-by-step explanation:

Find the common ratio for this geometric sequence. 243, 27, 3, 1/3, 1/27.​

Answers

Answer:

1/9

Step-by-step explanation:

Since each next term is 1/9 of the last, the common ratio is 1/9. This can be confirmed by the fact that 243*1/9=27, 27*1/9=3, 3*1/9=1/3, and so on. Hope this helps!

All math teachers are smart. Ms. Smith is your math teacher, so she is smart. What type of reasoning is this? inductive or deductive

Answers

Answer:

I believe it is Inductive Reasoning.

Step-by-step explanation:

Inductive Reasoning is a type of logical thinking that involves forming generalizations based on specific incidents you've experienced, observations you've made, or facts you know to be true or false.

Deductive Reasoning is a basic form of valid reasoning.

In two or more complete sentences, explain how to use ordered pairs of points in and to determine if and are inverses of each other.

Answers

For any point (x, y), that appears in one function, the point (y, x) must appear in the other function. 
For any point (x, y), that DOESN'T appear in one function, the point (y, x) must NOT appear in the other function. 
So if you find any point that DOESN'T meet the above rules, you can prove that the functions are NOT inverses of each other. 

But if you want to prove that they ARE inverses of each other, you have to check ALL points in the functions, and there are infinity of them, so that's not practical. Instead, you can write f(x) like this: 
y = 3x - 5 
Now solve for x: 
y + 5 = 3x 
x = (y + 5) / 3 
Now swap x and y: 
y = (x + 5) / 3 
This is the same as g(x). Therefore the functions are inverses of each other. oh

Please answer this correctly

Answers

Answer:

yes

Step-by-step explanation:

not every person is going to have the same opinion, so it is yes.

// have a great day //

Answer:

Yes, because if Pedro asked them the question "what do you think of public transportation?" the majority would probably say that they like it or something along those lines. This is biased because there may be other city inhabitants who don't think very highly of public transportation. Basically, what I'm trying to say is that not everyone will have the same opinion.

12x - y = -4
4x - 3y = -6 (1 point)

Answers

First step Substitute the value of y
4x-3(4+12x)= - 6
And this is your final answer

Answer:

Step-by-step explanation:

12x - y = -4  ----------------------(I)

4x - 3y = -6  ---------------------(II)

Multiply equation (I) by (-3)

(I)*(-3)                -36x + 3y = 12

(II)                       4x    - 3y = - 6  {Add and y will be eliminated}

                           - 32x     = 6

x = 6/-32

x = -3/16

Plugin the value of x in equation (I)

[tex]12*\frac{-3}{16} -y=-4\\\\3*\frac{-3}{4}-y=-4\\\\\frac{-9}{4}-y = -4\\\\-y=-4+\frac{9}{4}\\\\-y=\frac{-4*4}{1*4}+\frac{9}{4}\\\\-y=\frac{-16}{4}+\frac{9}{4}\\\\-y=\frac{-7}{4}\\\\y=\frac{7}{4}\\\\y=1\frac{3}{4}[/tex]

box + box + box equals to 30

OPTIONS (1,3,5,7,9,11,13,15)​

Answers

Step-by-step explanation:

[tex] \boxed{3!} + \boxed{9 }+ \boxed{15} = 30 \\ \because \: 3! = 3 \times 2 \times 1 = 6 \\ \therefore \: 6 + 9 + 15 = 30[/tex]

There are 5 gallons of distilled water in science supplies. If 8 students each use an equal amount of distilled water and there is 1 gallon left in supplies, how much will each student get?

Answers

Answer:

0.5 gallon

Step-by-step explanation:

let x refer to students

5 = 8x + 1

8x = 4

x= 0.5 gallon

Rearrange the following steps in the correct order to locate the last occurrence of the smallest element in a finite list of integers, where the integers in the list are not necessarily distinct.

a. return location
b. min ≔a1 and location ≔1
c. min ≔ai and location≔i
d. procedure last smallest(a1,a2,...,an: integers)
e. If min >= ai then

Answers

Answer:

The rearranged steps is as follows:

d. procedure last smallest(a1,a2,...,an: integers)

b. min ≔a1 and location ≔1

e. If min >= ai then

c. min ≔ai and location≔i

a. return location

Step-by-step explanation:

The proper steps to perform the task in the question above is dbeca

Here, the procedure (or function) was defined along with necessary parameters

d. procedure last smallest(a1,a2,...,an: integers)

The smallest number is initialized to the first number on the list and its location is initialized to 1

b. min ≔a1 and location ≔1

The next line is an if conditional statement that checks if the current smallest number is greater than a particular number

e. If min >= ai then

If the above condition is true, the smallest value is assigned to variable min; it's location is also assigned to variable location

c. min ≔ai and location≔i

The last step returns the location of the smallest number

a. return location

All the angles in the diagram are measured to the nearest degree. Work out the upper bound and lower bound of angle x 59 degree 108 degree 81 degree X degree ??????

Answers

Answer: lower bound, x = 110.5°

              upper bound, x = 113.5°

Step-by-step explanation:

There is no diagram but I am going to assume it is a quadrilateral since it has 4 angles. The sum of the angles of a quadrilateral is 360°.

           Upper       Lower

59°       58.5° ≤ a < 59.5

108°    107.5° ≤ b < 108.5°

81°       80.5° ≤ c < 81.5°  

Total:  246.6° ≤ x < 249.5°

Subtract the lower and upper bound totals from 360° :

                  360.0           360.0          

              -  246.5       - 249.5

x =              1 1 3.5           1 1 0.5

                      ↓                  ↓

                  upper            lower

                 bound            bound

Brand name producers of aspirin claim that one advantage of their aspirin over generic aspirin is that brand name aspirin is much more consistent in the amount of active ingredient used. This in turn means that users can expect the same results each time they use the brand name aspirin, while the effects of the generic aspirin can be a lot more variable. A random sample of 200 brand name aspirin tablets had a mean and standard deviation of active ingredient of 325.01 and 10.12 mg. A second independent sample of 180 generic aspirin tablets was measured for the amount of active ingredient, and the mean standard deviation were 323.47 and 11.43 mg. Given that the amount of active ingredient is normally distributed for both the brand name and the generic aspirin, do these data support the brand name producers claim? Let alpha = 0.025.

Answers

Answer:

Step-by-step explanation:

The claim here is that the brand name aspirin is more consistent in the amount of active ingredient used than the generic aspirin.

This is a test of 2 independent groups. The population standard deviations are not known. Let μ1 be the mean amount of active ingredients in brand name aspirin and μ2 be the mean amount of active ingredients in generic name aspirin

The random variable is μ1 - μ2 = difference in the mean amount of active ingredients between the brand name and generic aspirin

We would set up the hypothesis.

The null hypothesis is

H0 : μ1 ≥ μ2 H0 : μ1 - μ2 ≥ 0

The alternative hypothesis is

H1 : μ1 < μ2 H1 : μ1 - μ2 < 0

This is a left tailed test

Since sample standard deviation is known, we would determine the test statistic by using the t test. The formula is

(x1 - x2)/√(s1²/n1 + s2²/n2)

From the information given,

x1 = 325.01

x2 = 323.47

s1 = 10.12

s2 = 11.43

n1 = 200

n2 = 180

t = (325.01 - 323.47)/√(10.12²/200 + 11.43²/180)

t = 1.24

1.237877

The formula for determining the degree of freedom is

df = [s1²/n1 + s2²/n2]²/(1/n1 - 1)(s1²/n1)² + (1/n2 - 1)(s2²/n2)²

df = [10.12²/200 + 11.43²/180]²/[(1/200 - 1)(10.12²/200)² + (1/180 - 1)(11.43²/180)²] = 1.53233946713/0.00537245359

df = 285

We would determine the probability value from the t test calculator. It becomes

p value = 0.108

Since alpha, 0.025 < than the p value, 0.108, then we would fail to reject the null hypothesis. Therefore, at 2.5% level of significance, these data support the brand name producers claim

3.249 thousandths rounded to the nearest tenth

Answers

Answer: 3.2

Explanation: the tenths place is the 2 in 3.249. So if we want to round, we look at the hundredths place. Because 4 is in the hundreds place and 4 is less than 5, we round down to the tenths place. This means that 2 stays the same, and the decimal turns into 3.2

Answer:

3.2

Step-by-step explanation:

Rounded to the nearest 10

A piece of wire of length 7070 is​ cut, and the resulting two pieces are formed to make a circle and a square. Where should the wire be cut to​ (a) minimize and​ (b) maximize the combined area of the circle and the​ square?

Answers

Answer:

a.x=39.2

b.Use whole  wire as a circle

Step-by-step explanation:

We are given that

Length of piece of wire=70  units

Let length of wire used to make a square =x units

Length of wire used in circle=70- x

Side of square=[tex]\frac{perimeter\;of\;square}{4}=\frac{x}{4}[/tex]

Circumference of circle=[tex]2\pi r[/tex]

[tex]70-x=2\pi r[/tex]

[tex]r=\frac{70-x}{2\pi}[/tex]

Combined area of circle and square,A=[tex](\frac{x}{4})^2+\pi(\frac{70-x}{2\pi})^2[/tex]

Using the formula

Area of circle=[tex]\pi r^2[/tex]

Area of square=[tex](side)^2[/tex]

a.[tex]A=\frac{x^2}{16}+\frac{4900+x^2-140x}{4\pi}[/tex]

Differentiate w.r.t x

[tex]\frac{dA}{dx}=\frac{x}{8}+\frac{2x-140}{4\pi}[/tex]

[tex]\frac{dA}{dx}=0[/tex]

[tex]\frac{x}{8}+\frac{2x-140}{4\pi}=0[/tex]

[tex]\frac{\pi x+4x-280}{4\pi}=0[/tex]

[tex]\pi x+4x-280=0[/tex]

[tex]x(\pi+4)=280[/tex]

[tex]x=\frac{280}{\pi+4}[/tex]

x=39.2

Again differentiate w.r.t x

[tex]\frac{d^2A}{dx^2}=\frac{1}{8}+\frac{1}{2\pi}[/tex]>0

Hence, the combined area of circle and the square is minimum at x=39.2

b.When the wire is not cut and whole wire used  as a circle . Then, combined area is maximum.

Describe the steps to solve a rational equation. Create your own example and solve it following your steps. Then, provide an additional example for other people to try to solve as they reply to your post.

Answers

Answer:

Here is an exampls

Step-by-step explanation:

please help and please show your work

Answers

Answer:

The volume of all 9 spheres is 301.6 [tex]in^3[/tex]

Step-by-step explanation:

Notice that three of the identical spheres fit perfectly along the 12 in side box, therefore we know that the diameter of each is 12 in/3 = 4 in.

Then the radius of each sphere must be 2 inches (half of the diameter). Now that we know the radius of each sphere, we use the formula for the volume of a sphere to find it:

[tex]V=\frac{4}{3} \pi R^3\\V=\frac{4}{3} \pi (2\,in)^3\\V=\frac{4}{3} \pi\, 8\,\,in^3\\V=\frac{32}{3} \pi\,\,in^3[/tex]

Now, the total volume of all nine spheres is the product of 9 times the volume we just found:

[tex]V_{all \,9}=9\,*\frac{32}{3} \pi\,\,in^3\\V_{all \,9}=96 \pi\,\,in^3\\V_{all \,9}\approx \,301.6\,\,in^3[/tex]

You are standing 5 miles away from the peak. You look up at a 47-degree angle to the peak. How tall is the mountain? Hint: 5280 feet = 1 mile. Round your answer to the nearest foot.

Answers

Answer:

19272 feet

Step-by-step explanation:

We are given that the distance between the person and peak is 5 miles.

and angle is [tex]47^\circ[/tex] when we look up at the mountain peak.

The given situation is best represented as a right angled triangle as shown in the attached figure.

[tex]\triangle[/tex]IKJ where [tex]\angle K = 90^\circ[/tex]

IK is the mountain.

J is the point where we are standing.

Distance JI = 5 miles

[tex]\angle J = 47^\circ[/tex]

To find: Distance IK = ?

We can use trigonometric identities to find IK.

[tex]sin\theta = \dfrac{Perpendicular}{Hypotenuse}[/tex]

[tex]sinJ = \dfrac{IK}{JI}\\\Rightarrow sin47 = \dfrac{IK}{5}\\\Rightarrow IK = sin47^\circ \times 5\\\Rightarrow IK = 0.73 \times 5\\\Rightarrow IK = 3.65\ miles \\\Rightarrow IK = 3.65 \times 5280\ ft\\\Rightarrow IK = 19272\ ft[/tex]

Hence, height of mountain = 19272 ft

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