During the past year, on the average, 289 books were checked out daily from the public library in Stucco, Wyoming. This year, the city fathers of Stucco have attempted to increase circulation through various promotions such as bookmobiles, youth programs, and visits to local organizations. In order to evaluate their efforts, they have taken a random sample of 50 days of the current year and calculated the mean number of books checked out daily --288-- and the standard deviation--23. Based on this data, it is likely (95% confidence level) that the daily circulation of books has not increased? Please show math step by step. how you would put it in a TI-84 calculator to arrive at your answer

1.A sample of 80 is drawn from a population with a proportion equal to 0.50. Determine the probability of observing between 33 and 50 successes.

2.For a population that is left skewed with a mean of 27 and a standard deviation equal to 16​, determine the probability of observing a sample mean of 25 or more from a sample of size 37.

3. For a normal population with a mean equal to 80 and a standard deviation equal to 11​, determine the probability of observing a sample mean of 87 or less from a sample of size 11.

3.26Daily activity. It appears that people who are mildly obese are less active than leaner people. One study looked at the average number of minutes per day that people spend standing or walking.¹⁰ Among mildly obese people, minutes of activity varied according to the N(373, 67) distribution. Minutes of activity for lean people had the N(526, 107) distribution. Within what limits do the active minutes for about 95% of the people in each group fall? Use the 68–95–99.7 rule.

3.27Low IQ test scores. Scores on the Wechsler Adult Intelligence Scale (WAIS) are approximately Normal with mean 100 and standard deviation 15. People with WAIS scores below 70 are considered intellectually disabled when, for example, applying for Social Security disability benefits. According to the 68–95–99.7 rule, about what percent of adults are intellectually disabled by this criterion?

3.28Standard Normal drill.In each case, sketch a standard Normal curve and shade the area representing the region.

(a)z ≤ −2.15

(b)z ≥ −2.15

(c)z > 1.57

(d)−2.15 < z < 1.57

3.29Standard Normal drill.

(a)Find the number z such that the proportion of observations that are less than z in a standard Normal distribution is 0.3.

(b)Find the number z such that 35% of all observations from a standard Normal distribution are greater than z.

3.30Fruit flies. The common fruit fly Drosophila melano-gaster is the most studied organism in genetic research because it is small, is easy to grow, and reproduces rapidly. The length of the thorax (where the wings and legs attach) in a population of male fruit flies is approximately Normal with mean 0.800 millimeters (mm) and standard deviation 0.078 mm.

(a)What proportion of flies have thorax length less than 0.6 mm?

(b)What proportion have thorax length greater than 0.9 mm?

(c)What proportion have thorax length between 0.6 mm and 0.9 mm?

3.33A milling machine. Automated manufacturing operations are quite precise but still vary, often with distributions that are close to Normal. The width in inches of slots cut by a milling machine follows approximately the N(0.8750, 0.0012) distribution. The specifications allow slot widths between 0.8725 and 0.8775 inch. What proportion of slots meet these specifications?

3.37The middle half. The quartiles of any distribution are the values with cumulative proportions 0.25 and 0.75. They span the middle half of the distribution. What are the quartiles of the distribution of gas mileage?

3.44Grading managers. Some companies “grade on a bell curve” to compare the performance of their managers and professional workers. This forces the use of some low performance ratings so that not all workers are listed as “above average.” Ford Motor Company’s “performance management process” for this year assigned 10% A grades, 80% B grades, and 10% C grades to the company’s managers. Suppose Ford’s performance scores really are Normally distributed. This year, managers with scores less than 25 received C grades and those with scores above 475 received A grades. What are the mean and standard deviation of the scores?

Researchers are trying to estimate the proportion of patients trying a new experimental drug who experience a skin rash as a side-effect. 245 patients took this drug as part of early research, and these 245 patients are considered representative of the population who would take this drug in the future. 2.86% of these patients reported a skin rash. We would like to construct a 90% confidence interval for the proportion of potential drug users who would develop a skin rash.

What would be the standard error for our sample proportion, using the information we have from our sample to estimate that? Round to 3 decimal places

a 90% confidence interval will go 1.65 standard errors out in either direction. Calculate the lower bound of this 90% confidence interval for the true proportion of drug users who experience a skin rash as a side effect

For each scenario write the letter for what kind of hypothesis test or confidence interval is described. A. One sample z-test for a mean B. One sample t-test for a mean C. Matched pairs difference in means D. Two sample t-test for means independent E. One sample z-test for a proportion F. Two sample z-test for p1-p2 G. None of the above i. _______ An anthropology major believes the distribution of homes per city from the Anasazi Indians is normally distributed with a standard deviation of 12 homes. A random sample of 10 Anasazi cities shows an average of 46 homes. He wants an 85% confidence interval for the true overall average.

Refer to the table below. Given that 2 of the 127 subjects are randomly​ selected, complete parts​ (a) and​ (b).

    Rh +   Rh -
O   43   12
A   31   10
B   11   4
AB   13   3

a. Assume that the selections are made with replacement. What is the probability that the 2 selected subjects are both group AB and type Rh +?

b. Assume the selections are made without replacement. What is the probability that the 2 selected subjects are both group AB and type Rh+?

he weights of apples are normally distributed with a mean weight of 100 grams and standard deviation of 15 grams. If an apple is selected at random, what is the probability that its weight is:

PLEASE USE THE "NORMDIST" FUNCTION IN EXCEL

a) more than 111 grams;

b) between 97 and 107 grams;

c) at most 99 grams;

d) less than 98 or more than 105 grams;

e) exactly 97.8 grams;

f) exactly 87.8 or 106.9 grams;

g) not 112 grams;

h) at least 117 grams.

A population of values has a normal distribution with μ=99.5 and σ=83.2. You intend to draw a random sample of size n=197. Please answer the following questions, and show your answers to 1 decimal place.

Find P77, which is the value (X) separating the bottom 77% values from the top 23% values. P77 (for population) =

Find P77, which is the sample mean (¯x) separating the bottom 77% sample means from the top 23% sample means. P77 (for sample means) =

A fair coin is tossed 25 times. What is the probability that at least 1 tail occurs?

a) 1

b) 0.00000075

c) 0.99999923

d) 0.00000003

e) 0.99999997

f) None of the above.

A business organization needs to make up a 5 member fund-raising committee. The organization has 9 accounting majors and 7 finance majors. What is the probability that at most 2 accounting majors are on the committee?

a) 0.0151

b) 0.0048

c) 0.3654

d) 0.0103

e) 0.3606

f) None of the above.

A classroom of children has 17 boys and 19 girls in which five students are chosen at random to do presentations. What is the probability that more boys than girls are chosen?

a) 0.4448

b) 0.0164

c) 0.3249

d) 0.1199

e) 0.4284

f) None of the above.

A toy manufacturer inspects boxes of toys before shipment. Each box contains 9 toys. The inspection procedure consists of randomly selecting three toys from the box. If one or more of the toys are defective, the box is not shipped. Suppose that a given box has two defective toys. What is the probability that it will be shipped?

a) 0.4365

b) 0.0833

c) 0.0714

d) 0.5833

e) 0.4167

f) None of the above.

Compute the probability distribution, expectation, and variance of the following random variable:

- Multipliying the result of rolling two dice.

Title: At the 99% confidence level, what is the proportion of teenagers who play tennis?

____ 3.- Out of a sample of 120 teenagers, 14 of them responded YES to the question “Do you play tennis?” To answer the question in the title:

We would calculate a confidence interval centered at p_hat with a margin of error of 2.576*sqrt(0.12*(1-0.12)/120).

We would calculate a confidence interval centered at p with a margin of error of 2.576*sqrt(0.12*(1-0.12)/120).

We would calculate a significance test with z=sqrt(0.12*(1-0.12)/120).

We would calculate a significance test with Ho: p_hat=0.12.

Both c and d.

Eric wants to estimate the percentage of elementary school children who have a social media account. He surveys 450 elementary school children and finds that 280 have a social media account.

Identify the values needed to calculate a confidence interval at the 99% confidence level. Then find the confidence interval.

Use the table of common z-scores above.

• Round the final answer to three decimal places.

1. Estimate the labor hours required for a household with a moving size of 2000 CuFt and 6 Large Furniture
2. Based on the model output, we can say that both the size of the move (CuFt) and number of large furniture moved are important considerations when estimating the total number of labor hours required. We can make this claim because

• The FSTAT (F in the ANOVA Table) = 228.80, p-value (Sig.) is 0.00 = True or False?
• p-value for the slope coefficient of number of large furniture is 0.00 = True or False?
• p-value for the slope coefficient of the size of the mode (CuFt) is 0.00 = True or False?

3. Two households have the same moving volume (Cu Ft). One house has 5 large furniture to move while the second house has 8 large furniture to move. The average extra labor hours required for the second house is:

The lengths of pregnancies in a small rural village are normally distributed with a mean of 264 days and a standard deviation of 14 days.

In what range would you expect to find the middle 50% of most pregnancies?
Between  and .

If you were to draw samples of size 60 from this population, in what range would you expect to find the middle 50% of most averages for the lengths of pregnancies in the sample?
Between  and .

Enter your answers as numbers. Your answers should be accurate to 1 decimal places.

3. What is resource leveling and what might be the benefits to the project of being able to resource level?

4. List and describe the key elements of an e effective group?