In 2017, the top 5 Pop artists (so n_pop = 5) sold a mean number of 358,200 albums (SD = 227,656), and the top 5 R&B/Hip-Hop artists (so n_RBH = 5) sold a mean number of 352,600 albums (SD = 109,061).

Assuming conventional alpha, what is the critical value for the analysis that will help us judge whether these group means are significantly different?

Carbon monoxide​ (CO) emissions for a certain kind of car vary with mean 3.704 ​g/mi and standard deviation 0.7 ​g/mi. A company has 70 of these cars in its fleet. Let y overbary represent the mean CO level for the​ company's fleet. ​a) What's the approximate model for the distribution of y overbary​? Explain. ​b) Estimate the probability that y overbary is between 3.8 and 3.9​g/mi. ​c) There is only a 11​% chance that the​ fleet's mean CO level is greater than what​ value?

The state education commission wants to estimate the fraction of tenth grade students that have reading skills at or below the eighth grade level.

Step 2 of 2 :  

Suppose a sample of 333 tenth graders is drawn. Of the students sampled, 254 read above the eighth grade level. Using the data, construct the 80% confidence interval for the population proportion of tenth graders reading at or below the eighth grade level. Round your answers to three decimal places.

The Federal Reserve System publishes data on family income based on its Survey of Consumer Finances. When the head of the household has a college degree, the mean before-tax family income is $ 85,000. Suppose that 56% of the before-tax family incomes when the head of the household has a college degree are between $75,100 and $94,900 and that these incomes are normally distributed. What is the standard deviation of before-tax family incomes when the head of the household has a college degree?

A team of psychologists have developed an experimental treatment program for a learning disorder with the expectation that the treatment would enable recipients to score higher than before on a test of learning ability. To test the treatment, they randomly select a pool of 30 volunteers who have been diagnosed with the disorder and who have volunteered for the treatment program. Following treatment, the participants are retested on the learning ability test and their scores compared to earlier scores. Complete the following. (1 point each)

a. What statistical test would be appropriate in this case? Explain the rationale for your answer.

b. State the null and alternative hypotheses in words.

c. State the null and alternative hypotheses in statistical symbols

d. Would the test be right-tailed, left-tailed or two-tailed? Explain the rationale for your answer.

e. Describe a potentially confounding variable and explain how that might affect the conclusions from the study.

Explain the assumptions for using a two-independent sample t test. Provide an example for when you could use a a One-Sample t test. Provide an example for when a Two-Sample t Test.

1. According to a survey, working men reported doing 63.1 minutes of household chores a day, while working women reported tackling 81 minutes daily. But when examined more closely, millennial men reported doing just as many household chores as the average working women, 81 minutes, compared to an average of 55 minutes among both boomer men and Gen Xers. The information that follows is adapted from these data and is based on random samples of 1146 men and 795 women.

(a)

Construct a 95% confidence interval for the average time all men spend doing household chores. (Round your answers to one decimal place.)

minutes to minutes

(b)

Construct a 95% confidence interval for the average time women spend doing household chores. (Round your answers to one decimal place.)

minutes to minutes

2. A survey is designed to estimate the proportion of sports utility vehicles (SUVs) being driven in the state of California. A random sample of 500 registrations are selected from a Department of Motor Vehicles database, and 26 are classified as SUVs.

(a)

Use a 95% confidence interval to estimate the proportion of sports utility vehicles in California. (Round your answers to three decimal places.)

(b)

How can you estimate the proportion of sports utility vehicles in California with a higher degree of accuracy? (HINT: There are two answers. Select all that apply.)

increase the sample size n increase z_α/2 by decreasing the confidence coefficient conduct a non-random sample increase z_α/2 by increasing the confidence coefficient decrease z_α/2 by increasing the confidence coefficient decrease the sample size n decrease z_α/2 by decreasing the confidence coefficient

3.

A small amount of the trace element selenium, 50–200 micrograms (µg) per day, is considered essential to good health. Suppose that random samples of 40 adults were selected from two regions of the United States and that each person's daily selenium intake was recorded. The means and standard deviations of the selenium daily intakes for the two groups are shown in the table.

Find a 95% confidence interval for the difference

(μ₁ − μ₂)

in the mean selenium intakes for the two regions. (Round your answers to three decimal places.)

µg to µg

Interpret this interval.

We are 95% confident that the difference in the average daily selenium intake for the samples taken from Region 1 and Region 2 is within the interval. The probability that the difference in the average daily selenium intake for the populations in Region 1 and Region 2 is exactly in the middle of the interval is 95%.     We are 95% confident that the difference in the average daily selenium intake for the populations in Region 1 and Region 2 is within the interval. The probability that the difference in the average daily selenium intake for the populations in Region 1 and Region 2 is within the interval is 95%. The daily selenium intake is within the interval for 95% of the populations in Region 1 and Region 2.

4.

Does Mars, Incorporated use the same proportion of red candies in its plain and peanut varieties? A random sample of 59 plain M&M'S contained 13 red candies, and another random sample of 31 peanut M&M'S contained 9 red candies. (Use p₁ for the proportion of red candies in plain M&M'S and p₂ for the proportion of red candies in peanut M&M'S.)

(a)

Construct a 95% confidence interval for the difference in the proportions of red candies for the plain and peanut varieties

(p₁ − p₂).

(Round your answers to three decimal places.)

to

(b)

Based on the confidence interval in part (a), can you conclude that there is a difference in the proportions of red candies for the plain and peanut varieties? Explain.

Since the value p₁ − p₂ = 0 is not in the confidence interval, it is possible that p₁ = p₂. We should not conclude that there is a difference in the proportion of red candies in plain and peanut M&M'S. Since the value p₁ − p₂ = 0 is in the confidence interval, it is possible that p₁ = p₂. We should not conclude that there is a difference in the proportion of red candies in plain and peanut M&M'S.     Since the value p₁ − p₂ = 0 is in the confidence interval, it is very unlikely that p₁ = p₂. We should conclude that there is a difference in the proportion of red candies in plain and peanut M&M'S. Since the value p₁ − p₂ = 0 is not in the confidence interval, it is very unlikely that p₁ = p₂. We should conclude that there is a difference in the proportion of red candies in plain and peanut M&M'S.

    Case: Insourcing/Outsourcing — The FlexCon Piston Decision

1. Perform a quantitative insourcing/outsourcing analysis using the data provided. What qualitative issues might affect your final decision? Identify any costs or issues that are not part of your analysis that might affect your decision. What is your recommendation regarding what FlexCon should do with its family of pistons? Support your arguments with evidence gathered during your analysis.

2. Assume your group decided to outsource the pistons to the external supplier. Identify a plan that would enable FlexCon to carry out this recommendation. Be as thorough as possible.

3. Discuss the primary reasons when and why insourcing/outsourcing decisions occur.

4. A major challenge with an insourcing/outsourcing analysis involves gathering reliable data. Discuss the various groups that should be involved when conducting an insourcing/outsourcing analysis such as the one presented in this case. What information can each of these groups provide?

5. Discuss the major issues associated with an insourcing/outsourcing analysis and decision.

The bass in Clear Lake have weights that are normally distributed with a mean of 2.5 pounds and a standard deviation of 0.6 pounds.

(a) Suppose you only want to keep fish that are in the top 10% as far as weight is concerned. What is the minimum weight of a keeper? Round your answer to 2 decimal places.
____ pounds

(b) Suppose you want to mount a fish if it is in the top 0.5% of those in the lake. What is the minimum weight of a bass to be mounted? Round your answer to 2 decimal places.
____ pounds

(c) Determine the weights that delineate the middle 99% of the bass in Clear Lake. Round your answers to 2 decimal places.
from ____ to ____ pounds

For this problem, carry at least four digits after the decimal in your calculations. Answers may vary slightly due to rounding.

In a survey of 1000 large corporations, 248 said that, given a choice between a job candidate who smokes and an equally qualified nonsmoker, the nonsmoker would get the job.

(a) Let p represent the proportion of all corporations preferring a nonsmoking candidate. Find a point estimate for p. (Round your answer to four decimal places.)


(b) Find a 0.95 confidence interval for p. (Round your answers to three decimal places.)

(c) As a news writer, how would you report the survey results regarding the proportion of corporations that would hire the equally qualified nonsmoker?

Report the margin of error.Report p̂.    Report p̂ along with the margin of error.

What is the margin of error based on a 95% confidence interval? (Round your answer to three decimal places.)

A researcher wishes to study whether classical music has any affect on the ability to memorize information. A random sample of 51 adults were given a memory test in a quiet room. Then they were given a second memory test while listening to classical music. On the second test, 26 people received a higher score, 23 received a lower score, and 2 received the same score. A sign test at the 0.01 significance level will be used to test the claim that the music has no affect on memorization ability.

(a) What is the value of the test statistic used in this sign test?

(b) Give the value(s) of the critical value(s) used in this sign test. If there are two critical values, enter them both with a comma between them.

15-24: Consider the following values for the dependent and independent variables:

                                         x                                        y

                                         5                                       10

                                         15                                     15

                                         40                                     25

                                         50                                     44

                                         60                                     79

                                         80                                     112

1. Develop a scatter plot of the dat Does the plot suggest a linear or nonlinear relationship between the dependent and independent variables?
2. Develop an estimated linear regression equation for the data. Is the relationship significant? Test at an α=0.05 level.
3. Develop a regression equation of the form y^=b₀+b₁x+b₂x². Does this equation provide a better fit to the data than that found in part b?                    

please type answer so I can read it

In a study examining the survival of cancer patients, 100 patients were enrolled at baseline. After one year, 20 patients were known to have died. Assuming no patients were lost to follow-up, what was the probability of surviving one year? (OK to show numerator/denominator)What would be the one-year survival rate in the previous question if ten patients had been lost to follow-up during the first year? Use the life table method.

A researcher would like to predict the dependent variable YY from the two independent variables X1X1 and X2X2 for a sample of N=18N=18 subjects. Use multiple linear regression to calculate the coefficient of multiple determination and test the significance of the overall regression model. Use a significance level α=0.05α=0.05.

SSreg=SSreg=  
SSres=SSres=  
R2=R2=  
F=F=  
P-value =

What is your decision for the hypothesis test?

• Reject the null hypothesis, H0:β1=β2=0H0:β1=β2=0
• Fail to reject H0H0

What is your final conclusion?

• The evidence supports the claim that one or more of the regression coefficients is non-zero
• The evidence supports the claim that all of the regression coefficients are zero
• There is insufficient evidence to support the claim that at least one of the regression coefficients is non-zero
• There is insufficient evidence to support the claim that all of the regression coefficients are equal to zero

The Chamber of Commerce in a Canadian city has conducted an evaluation of 300 restaurants in its metropolitan area. Each restaurant received a rating on a 3-point scale on typical meal price (1 least expensive to 3 most expensive) and quality (1 lowest quality to 3 greatest quality). A crosstabulation of the rating data is shown below. Forty-two of the restaurants received a rating of 1 on quality and 1 on meal price, 39 of the restaurants received a rating of 1 on quality and 2 on meal price, and so on. Forty-eight of the restaurants received the highest rating of 3 on both quality and meal price.

(a)

Develop a bivariate probability distribution for quality and meal price of a randomly selected restaurant in this Canadian city. Let

x = quality rating

and

y = meal price.

(b)

Compute the expected value and variance for quality rating, x.

expected valuevariance

(c)

Compute the expected value and variance for meal price, y.

expected valuevariance

(d)

The

Var(x + y) = 1.6596.

Compute the covariance of x and y.

What can you say about the relationship between quality and meal price? Is this what you would expect?

Since the covariance is  ---Select--- positive negative zero , we  ---Select--- can can not conclude that as the quality rating increases, so does the meal price.

(e)

Compute the correlation coefficient between quality and meal price. (Round your answer to four decimal places.)

What is the strength of the relationship? Do you suppose it is likely to find a low-cost restaurant in this city that is also high quality? Why or why not?

The relationship between quality and meal price is  ---moderately negative or moderately positive or zero ---- and it  ---is or is not --- likley to find a low cost restaurant in this city that also has high quality.