1) An economist reports that 700 out of a sample of 2,800 middle-income American households actively participate in the stock market.[You may find it useful to reference the z table.]
  a. Construct the 90% confidence interval for the proportion of middle-income Americans who actively participate in the stock market. (Round intermediate calculations to at least 4 decimal places. Round "z" value and final answers to 3 decimal places.)  

b. Can we conclude that the percentage of middle-income Americans who actively participate in the stock market is not 28%?

Yes, since the confidence interval contains the value 0.28.

Yes, since the confidence interval does not contain the value 0.28.

No, since the confidence interval contains the value 0.28.

No, since the confidence interval does not contain the value 0.28.

Kyd and North are playing a game. Kyd selects one card from a standard 52-card deck. If Kyd selects a face card (Jack, Queen, or King), North pays him $6. If Kyd selects any other type of card, he pays North $3.

a) What is Kyd's expected value for this game? Round your answer to the nearest cent. $

b) What is North's expected value for this game? Round your answer to the nearest cent. $

Generally, the average typing speed is 56 words per minute (wp). A professor wanted to see where his students stand compared to the population. He tested 30 of his students and obtained the following estimates: an average typing speed of 49 with a standard deviation of 16. What can the professor conclude with α = 0.01?

a) What is the appropriate test statistic?
---Select--- na z-test One-Sample t-test Independent-Samples t-test Related-Samples t-test

b)
Population:
---Select--- the students student typing speed average typing speed typing speed the professor
Sample:
---Select--- the students student typing speed average typing speed typing speed the professor

c) Compute the appropriate test statistic(s) to make a decision about H₀.
(Hint: Make sure to write down the null and alternative hypotheses to help solve the problem.)
critical value =  ; test statistic =
Decision:  ---Select--- Reject H0 Fail to reject H0

Energy consumption: The following table presents the average annual energy expenditures (in dollars) for housing units of various sizes (in square feet), using the TI-84 Plus CE. The answer to the equation of the least-squares regression line is

=y=+b0b1x+984.09520.4819x.

.

The independaence postmaster suspects that working on ziptronic machines is the cause of high absenteeism. More than 10 absences from work without business related reason is considered excessive absenteeism. A check of employee recoreds shows that 26 of the 44 ziptronic operators had 10 or more absences and 35 of 120 nonziptronic workers had 10 or more absences. Construct a contingency table for the postmaster. Does the table support the postmaster’s suspicion that working on ziptronic machines is related to high absenteeism?

8. Seventy-five percent of the students graduating from high school in a small town in Oklahoma attend college. For a random sample of 50 students from the town, what is the probability that

a. at least 80% of the surveyed students will attend college?

b. between 80% and 85% (inclusive) of the surveyed students will attend college?

please explain thought process and step by step

A local greenhouse sells coffee-tree saplings. They price their saplings based on the height of the plant. They have two workers, Susan and Karen, who measure the saplings for pricing. The greenhouse manager wants to determine if there is a significant difference in the measurements made by these two individuals. She has them measure the same set of 15 saplings. Assume that the differences are calculated as Susan – Karen.

The resulting measurements (in cm) have been saved in StatCrunch. Use the data to compute the test statistic for the difference between Susan and Karen. For help using StatCrunch for a Paired Difference T-Test click here. (You may want to right-click that link and open it in a new window so you don't lose your answers on this quiz!)

Give your answer to four decimal places.

Susan   Karen difference
51.2381   51.5426   -0.3045
49.6311   49.292   0.3391
47.4822   46.9531   0.5291
50.3223   51.2982   -0.9759
46.3025   45.7606   0.5419
50.3047   50.3377   -0.033
50.4013   51.4663   -1.065
49.6507   50.0329   -0.3822
51.0187   50.985   0.0337
51.1941   51.7125   -0.5184
47.1907   47.6407   -0.45
49.7466   49.3111   0.4355
46.5283   47.3043   -0.776
47.2727   48.1091   -0.8364
51.5522   52.2639   -0.7117

Each of three supermarket chains in the Denver area claims to have the lowest overall prices. As part of an investigative study on supermarket advertising, a local television station conducted a study by randomly selecting nine grocery items. Then, on the same day, an intern was sent to each of the three stores to purchase the nine items. From the receipts, the following data were recorded. At the 0.025 significance level, is there a difference in the mean price for the nine items between the three supermarkets? Item Super's Ralph's Lowblaw's 1 $ 1.32 $ 1.87 $ 1.25 2 1.07 1.07 2.22 3 2.46 2.46 5.05 4 2.46 2.46 2.40 5 1.14 1.14 4.15 6 1.23 1.23 4.36 7 1.37 1.37 1.80 8 1.10 1.10 3.08 9 1.29 1.29 4.36 Click here for the Excel Data File State the null hypothesis and the alternate hypothesis. For Treatment (Stores): Null hypothesis H0: μ1 ≠ μ2 ≠ μ3 H0: μ1 = μ2 = μ3 a b Alternate hypothesis H1: There is no difference in the store means. H1: There is a difference in the store means. For blocks (Items): H0: μ1 = μ2 = ... μ9 H0: μ1 ≠ μ2 ≠ ... μ9 a b Alternate hypothesis H1: There is no difference in the item means. H1: There is a difference in the item means. What is the decision rule for both? (Round your answers to 2 decimal places.) Complete an ANOVA table. (Round your SS, MS to 3 decimal places, and F to 2 decimal places.) What is your decision regarding the null hypothesis? The decision for the F value (Stores) at 0.025 significance is: Reject H0 Do not reject H0 The decision for the F value (Items) at 0.025 significance is: Reject H0 Do not reject H0 Is there a difference in the item means and in the store means?

USA Today reported that about 47% of the general consumer population in the United States is loyal to the automobile manufacturer of their choice. Suppose Ford Motor Company did a study of a random sample of 1006 Ford owners and found that 490 said they would buy another Ford. Does this indicate that the population proportion of consumers loyal to Ford is more than 47%? Make conclusions at a 10% level of significance.

a) State the hypotheses to be tested.

b) Calculate and show the test statistic by hand.

c) Calculate the p-value using tables and illustrate the p-value by providing a graph showing appropriate area under the normal curve.

d) Confirm your results using Excel. Show Output.

e) Give your conclusions in a well-written sentence.

The distribution of results from a cholesterol test has a mean of 180 and a standard deviation of 20. A sample size of 40 is drawn randomly.

Find the probability that the sum of the 40 values is less than 6,950.

Question 1.

After several semesters of research, you finally decided to launch your own product idea online. According to your web hosting service, your clients spend about 14 minutes/week on your website. You believe an increase in the average-time-spend will increase your profits. Therefore, you decided to hire a fellow student to help you with your website. Formulate your hypothesis, identify the appropriate statistical test, and develop the decision rule to determine if your classmate adds value to your website given the following data: sample size: 101, x̄: 17.9, σ: 4.6, and a confidence level of 90%.

Can you please explain the logic to concluding to the correct answer?

Answer Part 1:

Fire your fellow student

or

Keep Your fellow student

BECAUSE.....

Answer Part 2:

a. the statistics suggests that he increase the average-time-spend on you website

b. the statistics suggests that he decrease the average-time-spend on you website

c. the statistics suggests that he doesn't add any value (accept H0)

Is the magnitude of an earthquake related to the depth below the surface at which the quake occurs? Let x be the magnitude of an earthquake (on the Richter scale), and let y be the depth (in kilometers) of the quake below the surface at the epicenter. Suppose a random sample of earthquakes gave the following information.

x 2.5 4 3.4 4.4 2.4

y 5.2 10.3 10.8 10.3 8.3

Compute r.

a. 0.098

b. -0.013

c. 0.752

d. 0.013

e. -0.752

You are conducting a test of the claim that the row variable and the column variable are dependent in the following contingency table.

Give all answers rounded to 3 places after the decimal point, if necessary.

(a) Enter the expected frequencies below:

(b) What is the chi-square test-statistic for this data?
      Test Statistic: χ2=χ2=

(c) What is the critical value for this test of independence when using a significance level of αα = 0.01?
      Critical Value: χ2=χ2=  

(d) What is the correct conclusion of this hypothesis test at the 0.01 significance level?

• There is not sufficient evidence to warrant rejection of the claim that the row and column variables are dependent.
• There is not sufficient evidence to support the claim that the row and column variables are dependent.
• There is sufficient evidence to warrant rejection of the claim that the row and column variables are dependent.
• There is sufficient evidence to support the claim that the row and column variables are dependent.

Remember to give all answers rounded to 3 places after the decimal point, if necessary.

Regression Assumptions

Below are some assumptions we must meet for regression. In one or two sentences, explain what each means.

Correctly specified model?

Linearity?

Minimum multicollinearity?

Homoscedastic distribution of errors?

1.Understand how to interpret values, such as lambda, gamma, etc.

2.When is Phi appropriate?

3.When Cramer’s V appropriate?

4.What values can phi take on?

5.What if the table is larger than 2x2?