Design study a nonexperimental, and then answer the following questions:

A. State your hypotheses and null hypotheses.
B. Identify and provide operational definitions of your variables.
C. Identify your population and describe your sample selection method and group assignment process.
D. Describe your nonexperimental design that you will use to test your hypotheses. This is the most important part of the midterm. Please be specific and clear.
E.What are some confounding variables and how will you control for them?
it have to be QUASİ, use your own words

Vintage Coffee Co. produces three products: coffee beans, tea bags, and chai. The following monthly information is available regarding Vintage's manufacturing costs and production volumes.

1. Using Excel, prepare a multiple regression analysis to estimate total manufacturing costs using coffee, tea bags, and chai.

2. What is the cost-estimating equation based on your multiple regression analysis?

3. How much of the variation in monthly cost is explained by your cost-estimating equation? Do you think that this equation does a good job estimating production costs? Why or why not.

4. Based on the regression output, are you confident that each of the independent variables affects the total manufacturing costs? Why or why not?

5. Vintage plans to produce 14,000 pounds of coffee beans, 11,000 teabags, and 1,600 boxes of chai in May 2020. Using your cost-estimating equation, what is the estimated total manufacturing cost for May 2020?

6. You have a special-order opportunity (assume that you have sufficient excess capacity to complete the order). A customer has offered to buy 500 boxes of chai for $225 per box. You normally sell chai for $275 per box. Should you accept the order? Why or why not.

An experimenter was interested in dieting and weight loss among men and women. It was believed that women tend to lose more weight than men in the first 2 weeks of a standard dieting program. A random sample of 15 married coupes were put on the same diet. Their weight loss after 2 weeks is listed below. Conduct a directional t-test of the difference using .05 as your level of significance. Be sure to complete all steps.

Wives (pounds)

2.7,4.4,3.5,3.7,5.6,5.1,3.8,3.5,5.6,4.2,6.3,4.4,3.9,5.1,3.4

Husbands (pounds)

5.0,3.3,4.3,6.1,2.5,1.9,3.2,4.1,4.5,2.7,7.0,1.5,3.7,5.2,1.9

Aptitude tests should produce scores with a large amount of variation so that an administrator can distinguish between persons with low aptitude and persons with high aptitude. Two tests used by a certain industry are given. There are 21 subjects who receive the first test with a standard deviation of 10.3 points and 23 subjects who receive the second test with a standard deviation of 12.4 points. Is there sufficient evidence to conclude that there is a difference in the variability of the two tests? USE CHI-SQUARE and report the p-value.

A consumer agency claims that the average fuel mileage of Sedan A exceeds that of Sedan B. To test this claim, a random sample of 17 Sedan A vehicles were tested and the sample mean fuel mileage was found to be 28.25 miles per gallon with a known population standard deviation of 1.30 miles per gallon. A random sample of 14 Sedan B vehicles also were tested and the sample mean fuel mileage was found to be 27.25 miles per gallon with a known population standard deviation of 1.35 miles per gallon. Use a 1% significance level and assume the fuel mileage values for each of the two populations of sedans are normally distributed.

a. Select the correct symbol to replace "?" in the null hypothesis H₀: μ_A − μ_B? 0

b. Select the correct symbol to replace "?" in the alternative hypothesis H_a: μ_A − μ_B? 0

c. Compute the value of the test statistic used to test the agency's claim.

Do not round any intermediate calculations. Round your answer to two decimal places. Enter a "−" sign directly before a negative answer.

Test statistic =

d. Determine the critical value used to test the agency's claim.

Enter your critical value to three decimal places. Enter a "−" sign directly before a negative answer.

Critical value =

e.  Compute the p-value for this hypothesis test.

Use your rounded test statistic from Part c. Do not round any other intermediate calculations. Round your final answer to four decimal places.

p-value =

f. Based on the above results, choose the appropriate initial conclusion.

g. Based on the claim and your initial conclusion, choose the appropriate final conclusion.

The Bureau of Labor Statistics reported that the average yearly income of dentists in the year 2012 was $110,000.  A sample of 81 dentists, which was taken in 2013, showed an average yearly income of $120,000.  Assume the standard deviation of the population of dentists’ incomes in 2013 is $36,000.

In a survey of 3,654 ​travelers, 1,456 said that location was very important for choosing a hotel and1,210 said that reputation was very important in choosing an airline. Complete parts ​(a) and (b) below.

a. Construct a 90% confidence interval estimate for the population proportion of travelers who said that location was very important for choosing a hotel.

b. Construct a 90% confidence interval estimate for the population proportion of travelers who said that reputation was very important in choosing an airline.

Hogwarts has 4 houses (Gryffindor, Hufflepuff, Ravenclaw, Slytherin). We can represent them by their first letters G H R S. Each house has exactly 20 students. If I choose 4 students randomly, what is the probability that I have one from each house?

14) The selling prices of mutual funds change daily. In order to study these changes, a sample of mutual funds was examined and the daily changes in price are listed below. (Round answers to 3 decimal places). 0.32, -0.17, 0.26, -0.03, -0.01, 0.18, 0.33, 0.28, 0.02, -0.29, -0.08, 0.12, 0.07, 0.03, 0.28

a)  Using a calculator find Q1, Q3, median and IQR

b) Determine the lower and upper fences. (Show work)

(c) Identify the outliers (if any) in this set (Credit only if parts (a) and (b) are correct)

8. To monitor the manufacturing process of rubber support bearings used between the super- structure and foundation pads of nuclear power plants, a quality control engineer randomly sampled 100 bearings from the production line each day over a 15-day period. The bear- ings were inspected and the number of defects was found. The number of defects in your personalised data set are as follows:

        1, 12, 3, 4, 4, 2, 4, 5, 4, 1, 9, 3, 3, 2, 2
   

   1. (a) Use R to plot the appropriate control chart to check if the proportion of non-conforming units was in control.

   2. (b) Using manual working, verify that the control limits are what you expect them to be.

   3. (c) Assuming the assignable cause of variations have been found, construct a control chart that can be used to monitor the non-conforming proportion on future days of the process.

In the discrimination case Connecticut v. Teal, the following data were given concerning a CT state agency's record of employees rejected or selected for promotion.

In discrimination cases, sometimes the blacks and whites described in such a table are viewed as samples from theoretical populations that might result if large numbers of blacks and whites were considered for promotion by the agency. Test the claim that the population of whites selected for promotion is larger than that of blacks at 2.5% level of significance.

A study was made on the amount of converted sugar in a certain process at various temperatures. The data were coded and recorded as follows:

a) Estimate the linear regression line.
b) Estimate the mean amount of converted sugar produced when the coded temperature is 1.75.
c) Plot the residuals versus temperature. Comment.
d) Compute SSE and estimate the variance.
e) Construct a 95% confidence interval for intercept;
f) Construct a 95% confidence interval for slope.
g) Use an ANOVA approach to test the hypothesis that slope = 0 against the alternative hypothesis slope ≠ 0 at the 0.05 level of significance.

For questions 1 and 2, refer to the following: The Federal Trade Commission provided measured tar contents (in mg) of randomly selected filtered and nonfiltered king-size cigarettes. A random sample of 21 filtered king-size cigarettes has a mean tar content of 13.3 mg with standard deviation 3.7 mg. A random sample of 8 nonfiltered king-size cigarettes has a mean tar content of 24.0 mg with standard deviation 1.7 mg. Assuming unequal variances between the two populations of cigarettes, you need to test the claim that the mean amount of tar in filtered king-size cigarettes is less than the mean amount of tar in nonfiltered king-size cigarettes at a

0.05 significance level.

1. What is the most appropriate statistical test?
   1. Two-sample z-test
   2. Two-sample t-test (pooled variance)
   3. Two-sample t-test (unpooled variance)
   4. Paired t test
   5. Two-way ANOVA

2. What should you use for the value of the test statistic?

a. -17.16

b. -10.70

c. -10.63

d. -7.80

e. -1.90

(1 point) Fueleconomy.gov, the official US government source for fuel economy information, allows users to share gas mileage information on their vehicles. The histogram below shows the distribution of gas mileage in miles per gallon (MPG) from 14 users who drive a 2012 Toyota Prius. The sample mean is 53.3 MPG and the standard deviation is 5.2 MPG. Note that these data are user estimates and since the source data cannot be verified, the accuracy of these estimates are not guaranteed. Report all answers to 4 decimal places.

1. We would like to use these data to evaluate the average gas mileage of all 2012 Prius drivers. Do you think this is reasonable? Why or why not?

? Yes No , because  ? the data distribution seems approximately normal there are 14 data points in the sample user estimates are reliable user estimates are not reliable .

The EPA claims that a 2012 Prius gets 50 MPG (city and highway mileage combined). Do these data provide strong evidence against this estimate for drivers who participate on fueleconomy.gov? Conduct a hypothesis test. Round numeric answers to 3 decimal places where necessary.

2. What are the correct hypotheses for conducting a hypothesis test to determine if these data provide strong evidence against this estimate for drivers who participate on fueleconomy.gov? (Reminder: check conditions)

A. ?0:?=50H0:μ=50 vs. ??:?≠50HA:μ≠50
B. ?0:?=50H0:μ=50 vs. ??:?>50.3HA:μ>50.3
C. ?0:?=53.3H0:μ=53.3 vs. ??:?≠53.3HA:μ≠53.3
D. ?0:?=50.3H0:μ=50.3 vs. ??:?<50HA:μ<50

3. Calculate the test statistic.

4. Calculate the p-value.

5. How much evidence do we have that the null model is not compatible with our observed results?

A. some evidence
B. little evidence
C. extremely strong evidence
D. strong evidence
E. very strong evidence

6. Calculate a 95% confidence interval for the average gas mileage of a 2012 Prius by drivers who participate on fueleconomy.gov.

( ,  )