Transplant operations have become routine. One common transplant operation is for kidneys. The most dangerous aspect of the procedure is the possibility that the body may reject the new organ. There are several new drugs available for such circumstances and the earlier the drug is administered, the higher the probability of averting rejection. The New England Journal of Medicine recently reported the development of a new urine test to detect early warning signs that the body is rejecting a transplanted kidney. However, like most other tests, the new test is not perfect. In fact, 20% of negative tests and 9% of positive tests prove to be incorrect. Physicians know that in about 32% of kidney transplants the body tries to reject the organ. If the new test has a positive result (indicating early warning of rejection), what is the probability that the body is attempting to reject the kidney?

The Donner Party: Natural Selection in Action The Donner Party is the name of emigrants who travelled in covered wagons from Illinois to California in 1846 and became trapped in the Sierra Nevada Mountains when the region was hit by heavy snows in late October. By the time the survivors were rescued in April, 1847, 40 out of 87 had died from famine and exposure to severe cold. Some of those that survived did so by resorting to cannibalism, according to newspapers reporting at that time. Data on the survivorship of the party members may be used to gain some insight into human behavior and natural selection under extreme stress. For example, some questions of interest are whether males are better able to withstand harsh conditions than females and the extent to which the chances of survival vary with age. The data in the lab assignment come from Grayson, (1990), “Donner Party Deaths: A Demographic Assessment,” Journal of Anthropological Research, v.46. The data are also available in the StatCrunch file lab3.txt located on the STAT 151 Laboratories web site at http://www.stat.ualberta.ca/statslabs/stat151/index.htm (click Stat 151 link, and Data for Lab 3). The data are not to be printed in your submission. The following is a description of the variables in the data file: Variable Name Description of Variable NAME full name of the passenger, GENDER gender (female or male); FAMILY family name, POSITION member status within the family, AGE estimated age (in years) as of July 31, 1846; CHILD child (yes or no) SURVIVAL survived or died, ORDER order of death, ALONE Yes if travelling alone (no family, no close accompanying persons), GROUP SIZE Number of group members. 1. Is it an observational study or a randomized experiment? Can the data be generalized to a broader population? If females in the study turned out to be more apt to survive than males, could this be used as proof that, in general, females are better able than males to withstand harsh conditions? 4. In this question, you will examine the relationship between survival and gender. (a) Were the chances of survival different for females than for males? In order to answer the question, obtain the contingency table of survival by gender. Make sure that Row percent, Column percent, and Percent of Total as well as Chi-Square test for independence are selected. Paste the table into your report. (b) Using α = 0.05, test that there was no relationship between survival and gender. State the null and alternative hypotheses. Report the value of the appropriate test statistic, the distribution of the test statistic under the null hypothesis, and the P-value of the test to answer the question. State your conclusion. (c) Refer to the output in part (a) to answer the following questions: What percent of the survivors were females? What percent were female survivors? (d) Using α = 0.05, is there evidence that there was a difference in the survival rate for females and males? Carry out the appropriate two-sample proportion test. State the null and alternative hypotheses. Report the value of the appropriate test statistic, the distribution of the test statistic under the null hypothesis, and the P-value of the test to answer the question. State your conclusion. (e) What is the relationship between the tests in parts (b) and (d)? 3 (f) Obtain and interpret a 95% confidence interval for the difference in survival rates of females and males?

4. Below is the amount that a sample of 15 customers spent for lunch ($) at a fast-food restaurant: 7.42 6.29 5.83 6.50 8.34 9.51 7.10 5.90 4.89 6.50 5.52 7.90 8.30 9.60 6.80 Recall the lunch at a fast-food restaurant problem from Assignment 4. Let µ represent the population mean amount spent for lunch ($) at a fast-food restaurant. Previously you calculated the mean and standard deviation of the fifteen sample measurements to be x ̅ = $7.09 and s = $1.406, respectively. Suppose you want to determine if the true value of µ differs from $7.50. Specify the null and alternative hypotheses for this test. Since x ̅ = $7.09 is less than $7.50, a manger wants to reject the null hypothesis. What are the problems with using such a decision rule? Compute the value of the test statistic. Find the approximate p-value of the test or use technology to find the exact p-value. Select a value of α, the probability of a Type I error. What does α represent in the words of the problem. Give the appropriate conclusion, based on the results of parts d and e. What conditions must be satisfied for the test results to be valid? In Assignment 4, you found a 95% confidence interval for µ. Does this interval support your conclusion in part f?

PLEASE SHOW ANSWER WITHOUT USING EXCEL OR ANY SOFTWARE. NEED DETAILED WORKINGS OF THE ANSWER. PLEASE NOTE NO EXCEL

The manager of a computer software company wishes to study the number of hours senior executives by type of industry spend at their desktop computers. The manager selected a sample of five executives from each of three industries. At the .05 significance level, can she conclude there is a difference in the mean number of hours spent per week by industry?

PLEASE SHOW ANSWER WITHOUT USING EXCEL OR ANY SOFTWARE. NEED DETAILED WORKINGS OF THE ANSWER. PLEASE NOTE NO EXCEL

Because of staffing decisions, managers of the Gibson-Marimont Hotel are interested in the variability in the number of rooms occupied per day during a particular season of the year. A sample of 24 days of operation shows a sample mean of 294 rooms occupied per day and a sample standard deviation of 26 rooms.

What is the point estimate of the population variance? 676

Provide a 90% confidence interval estimate of the population variance (to 1 decimal). ( , )

Provide a 90% confidence interval estimate of the population standard deviation (to 1 decimal). ( , )

A cell phone manufacturer claims that the batteries in its latest model provide 20 hours of continuous use. In order to verify this claim, and independent testing firm checks the battery life of 100 phones. They find that the batteries in these 100 phones last an average of 19 hours with a standard deviation of 5 hours. Conduct an appropriate hypothesis test to check whether the results from this sample provide sufficient evidence that the true mean battery life is significantly less than 20 hours.

1. Is this a question about the sample mean or the sample proportion? Explain how you know.

2. What is the most appropriate test, a two-tailed test, a right-tailed test, or a left-tailed test? Explain how you know.

3. State the null and alternative hypotheses. Make sure to use proper notation.

4. Calculate the test statistic. Make sure to show all your computations.

5. Determine the P-value. Make sure to explain how you obtained the value.

f. State the decision about the null hypothesis as well as the conclusion from your hypothesis test in the context of the problem.

QUESTION (please show your work so that I may understand how to do the problem) thanks Before you can calculate your test statistic, you’ll have to calculate the SEM. Use the formula in the book/lecture to calculate the SEM. Put your value below. Remember that you will need to calculate the population standard deviation first (remember to use n rather than n-1 for the population standard deviation calculation). Round your response out to two decimal places, if you give more than two decimal places Canvas may count your answer as wrong Pat is the manager of a real estate group that is part of a larger real estate company. Here are the total number of home sales from 2018 for all the agents at the entire company. 4, 5, 10, 4, 6, 7, 9, 11, 3, 4, 8, 9, 2, 4, 3, 12, 4, 5, 6, 3, 8, 9, 8, 7, 10, 4, 5, 7, 8, 6. Pat wants to know if her own real estate group, which has 4 agents (the sample, in this case), has sold more homes than the rest of the company (the population). Your job is to tell me if these four agents (agents A, B, C, and D) differ in number of home sales from the population (the entire company). Remember that you need to calculate the population standard deviation first! Agent Number of Homes Sold in 2018 A 6 B 7 C 8 D 10

1- State the null hypothesis

Group of answer choices

a-H₀: The sample drawn from the population reflects the population, or M = µ

b-H₀: The sample drawn from the population reflects the population, or M ≠ µ

2- State the alternative hypothesis

Group of answer choices

a-H₁: The sample drawn from the population does not reflect the population, or M ≠ µ

b-H₁: The sample drawn from the population reflects the population, or M = µ

3- Determine the best statistical test to use

Group of answer choices

a-Critical value test

b-Z score test

c-Correlational test

d-one-sample Z test

4-Before you can calculate your test statistic, you’ll have to calculate the SEM. Use the formula in the book/lecture to calculate the SEM. Put your value below. Remember that you will need to calculate the population standard deviation first (remember to use n rather than n-1 for the population standard deviation calculation). Round your response out to two decimal places, if you give more than two decimal places Canvas may count your answer as wrong.

5-Now, Compute the test statistic (Use the formulas in the book / lecture to calculate the correct statistic). Which of the following is the correct value?

Group of answer choices

a-z = 0.171

b-z =1.06

c-z = 3.505

d-z = 1.04

6- The value needed to reject the null hypothesis is ___________.

Group of answer choices

a-1.64

b-1.96

c-3.25

d-2.10

7-Does the obtained value exceed the critical value (that is, is the obtained value larger than the critical value)?

Group of answer choices

a-No

b-Yes

8- Based on your answer to the previous question, the decision is to ____________

Group of answer choices

a-Reject the null hypothesis

b-Fail to reject the null hypothesis

Two plots at Rothamsted Experimental Station were studied for production of wheat straw. For a random sample of years, the annual wheat straw production (in pounds) from one plot was as follows.

Use a calculator to verify that, for this plot, the sample variance is s² ≈ 0.312.

Another random sample of years for a second plot gave the following annual wheat production (in pounds).

Use a calculator to verify that the sample variance for this plot is s² ≈ 0.385.

Test the claim that there is a difference (either way) in the population variance of wheat straw production for these two plots. Use a 5% level of signifcance.

(a) What is the level of significance?

State the null and alternate hypotheses.

H_o: σ₁² = σ₂²; H₁: σ₁² > σ₂²

H_o: σ₁² > σ₂²; H₁: σ₁² = σ₂²

H_o: σ₂² = σ₁²; H₁: σ₂² > σ₁²

H_o: σ₁² = σ₂²; H₁: σ₁² ≠ σ₂²

(b) Find the value of the sample F statistic. (Use 2 decimal places.)


What are the degrees of freedom?

What assumptions are you making about the original distribution?

The populations follow independent normal distributions. We have random samples from each population.

The populations follow dependent normal distributions. We have random samples from each population.    

The populations follow independent normal distributions.

The populations follow independent chi-square distributions. We have random samples from each population.

(c) Find or estimate the P-value of the sample test statistic. (Use 4 decimal places.)

p-value > 0.200

0.100 < p-value < 0.200     

0.050 < p-value < 0.100

0.020 < p-value < 0.050

0.002 < p-value < 0.020

p-value < 0.002

(d) Based on your answers in parts (a) to (c), will you reject or fail to reject the null hypothesis?

At the α = 0.05 level, we reject the null hypothesis and conclude the data are not statistically significant

.At the α = 0.05 level, we reject the null hypothesis and conclude the data are statistically significant.     

At the α = 0.05 level, we fail to reject the null hypothesis and conclude the data are not statistically significant.

At the α = 0.05 level, we fail to reject the null hypothesis and conclude the data are statistically significant.

(e) Interpret your conclusion in the context of the application.

Fail to reject the null hypothesis, there is sufficient evidence that the variance in annual wheat production differs between the two plots.

Reject the null hypothesis, there is insufficient evidence that the variance in annual wheat production differs between the two plots.     

Reject the null hypothesis, there is sufficient evidence that the variance in annual wheat production differs between the two plots.

Fail to reject the null hypothesis, there is insufficient evidence that the variance in annual wheat production differs between the two plots.

assume a normal distribution with a mean of 65 and standard deviation of 14 find P(56<X less than or equal to 68)

A tire company produced a batch of 5 comma 300 tires that includes exactly 260 that are defective. a. If 4 tires are randomly selected for installation on a​ car, what is the probability that they are all​ good? b. If 100 tires are randomly selected for shipment to an​ outlet, what is the probability that they are all​ good? Should this outlet plan to deal with defective tires returned by​ consumers?

Suppose the lengths of the pregnancies of a certain animal are approximately normally distributed with mean mu equals 127 days and standard deviation sigma equals 12 days. Complete parts​ (a) through​ (f) below. ​(a) What is the probability that a randomly selected pregnancy lasts less than 123 ​days? The probability that a randomly selected pregnancy lasts less than 123 days is approximately 0.3694. ​(Round to four decimal places as​ needed.) Interpret this probability. Select the correct choice below and fill in the answer box within your choice. ​(Round to the nearest integer as​ needed.) A. If 100 pregnant individuals were selected independently from this​ population, we would expect 37 pregnancies to last less than 123 days. B. If 100 pregnant individuals were selected independently from this​ population, we would expect nothing pregnancies to last more than 123 days. C. If 100 pregnant individuals were selected independently from this​ population, we would expect nothing pregnancies to last exactly 123 days. ​(b) Suppose a random sample of 20 pregnancies is obtained. Describe the sampling distribution of the sample mean length of pregnancies. The sampling distribution of x overbar is normal with mu Subscript x overbarequals 127 and sigma Subscript x overbarequals 2.9104. ​(Round to four decimal places as​ needed.) ​(c) What is the probability that a random sample of 20 pregnancies has a mean gestation period of 123 days or​ less? The probability that the mean of a random sample of 20 pregnancies is less than 123 days is approximately nothing. ​(Round to four decimal places as​ needed.) Interpret this probability. Select the correct choice below and fill in the answer box within your choice. ​(Round to the nearest integer as​ needed.) A. If 100 independent random samples of size nequals20 pregnancies were obtained from this​ population, we would expect nothing ​sample(s) to have a sample mean of 123 days or less. B. If 100 independent random samples of size nequals20 pregnancies were obtained from this​ population, we would expect nothing ​sample(s) to have a sample mean of 123 days or more. C. If 100 independent random samples of size nequals20 pregnancies were obtained from this​ population, we would expect nothing ​sample(s) to have a sample mean of exactly 123 days. ​(d) What is the probability that a random sample of 39 pregnancies has a mean gestation period of 123 days or​ less? The probability that the mean of a random sample of 39 pregnancies is less than 123 days is approximately nothing. ​(Round to four decimal places as​ needed.) Interpret this probability. Select the correct choice below and fill in the answer box within your choice. ​(Round to the nearest integer as​ needed.) A. If 100 independent random samples of size nequals39 pregnancies were obtained from this​ population, we would expect nothing ​sample(s) to have a sample mean of 123 days or less. B. If 100 independent random samples of size nequals39 pregnancies were obtained from this​ population, we would expect nothing ​sample(s) to have a sample mean of exactly 123 days. C. If 100 independent random samples of size nequals39 pregnancies were obtained from this​ population, we would expect nothing ​sample(s) to have a sample mean of 123 days or more. ​(e) What might you conclude if a random sample of 39 pregnancies resulted in a mean gestation period of 123 days or​ less? This result would be ▼ expected, unusual, so the sample likely came from a population whose mean gestation period is ▼ less than equal to greater than 127 days. ​(f) What is the probability a random sample of size 15 will have a mean gestation period within 12 days of the​ mean? The probability that a random sample of size 15 will have a mean gestation period within 12 days of the mean is nothing. ​(Round to four decimal places as​ needed.)

n Ecological Engineering, the potential for floating aquatic plants to treat dairy manure wastewater was investigated. For one part of the study, 16 treated wastewater samples were randomly divided into two groups- a control algal was cultured in half the samples and the water hyacinth was cultured in the other half. The rate of increase in the amount of total phosphorus was measured in each water sample. The control algal had a sample mean of 0.036 with a standard deviation of 0.008 while the water hyacinth had a sample mean of 0.026 with a standard deviation of 0.006. Conduct a test to determine if there is a difference in mean rates of increase of total phosphorus for the two aquatic plants. Use alpha = 0.05.

1) What type of test should be conducted?

The town of Pleasantville is going to form a public safety committee. Pleasantville already has a seven-person town council, a five-person citizen advisory board; the police force is made up of ten officers. There is no overlap between the members of the town council, the citizen advisory board, and the police force.
Express all probabilities as decimals, rounded to six places.

14) If the committee must include three members from the town council, two members from the citizen advisory board, and three members from the police force, how many different ways can the committee be formed?

b) Suppose the public safety committee is made up as described in #14, and members are to be chosen at random from each of the town council, advisory board, and police force. If Tayler is on the town council, what is the probability they will be selected for the committee?

c) Suppose the public safety committee is made up as described in #14, and members are to be chosen at random from each of the town council, advisory board, and police force. If Casey is on the citizen advisory board, what is the probability they will be selected for the committee?

d) Suppose the public safety committee is made up as described in #14, and members are to be chosen at random from each of the town council, advisory board, and police force. If Pat is a police officer, what is the probability they will be selected for the committee?

3-2-1kathleen wants to know whether height and shoe size are realted in women. She stops and surveys some female students on the quad and finds the following information:

1)what is the covariance of there data?

2)What is the coefficient of correlation of these data?

3)What is the relationship between the two variables?

a. Can't be determined

b. Weakly positive

c. Strongly positive

d. Moderately negative