Consider the following data drawn independently from normally distributed populations: (You may find it useful to reference the appropriate table: z table or t table)

a. Construct the 95% confidence interval for the difference between the population means. (Negative values should be indicated by a minus sign. Round all intermediate calculations to at least 4 decimal places and final answers to 2 decimal places.)

b. Specify the competing hypotheses in order to determine whether or not the population means differ.

• H₀: μ₁ − μ₂ = 0; H_A: μ₁ − μ₂ ≠ 0

• H₀: μ₁ − μ₂ ≥ 0; H_A: μ₁ − μ₂ < 0

• H₀: μ₁ − μ₂ ≤ 0; H_A: μ₁ − μ₂ > 0

c. Using the confidence interval from part a, can you reject the null hypothesis?

• Yes, since the confidence interval includes the hypothesized value of 0.

• No, since the confidence interval includes the hypothesized value of 0.

• Yes, since the confidence interval does not include the hypothesized value of 0.

• No, since the confidence interval does not include the hypothesized value of 0.

d. Interpret the results at   αα = 0.05.

• We conclude that the population means differ.

• We cannot conclude that the population means differ.

• We conclude that population mean 2 is greater than population mean 1.

• We cannot conclude that population mean 2 is greater than population mean 1.

Please provide an example and then discuss how regression analysis may be used as a forecasting tool.

Thank you.

Indicate whether each measure is a nominal, ordinal, or interval/ratio measure. Explain the reasons for your choices:

a. inches in a yardstick:

b. Virginia driver’s license customer ID:

c. dollars as a measure of income:

d. order of finish in a horse race:

e. intelligence test scores:

Longwave (LW) and shortwave (SW) are two appearance measures used in the automotive industry to rate the quality of a paint job. These two measures are generally related. Values for 13 cars are given. Use these data to answer the following:

What value represents the coefficient of correlation between the LW and SW appearances?

Group of answer choices

0.8199

0.6723

0.3461

0.124

It is thought that prehistoric Indians did not take their best tools, pottery, and household items when they visited higher elevations for their summer camps. It is hypothesized that archaeological sites tend to lose their cultural identity and specific cultural affiliation as the elevation of the site increases. Let x be the elevation (in thousands of feet) of an archaeological site in the southwestern United States. Let y be the percentage of unidentified artifacts (no specific cultural affiliation) at a given elevation. The following data were obtained for a collection of archaeological sites in New Mexico. x 5.17 5.87 6.25 6.75 7.25 y 20 11 33 37 62 Complete parts (a) through (e), given Σx = 31.29, Σy = 163, Σx2 = 198.3733, Σy2 = 6823, Σxy = 1073.47, and r ≈ 0.859. (a) Draw a scatter diagram displaying the data. Get Flash Player Flash Player version 10 or higher is required for this question. You can get Flash Player free from Adobe's website. (b) Verify the given sums Σx, Σy, Σx2, Σy2, Σxy, and the value of the sample correlation coefficient r. (Round your value for r to three decimal places.) Σx = Σy = Σx2 = Σy2 = Σxy = r = (c) Find x, and y. Then find the equation of the least-squares line y hat = a + bx. (Round your answers for x and y to two decimal places. Round your answers for a and b to three decimal places.) x = y = y hat = + x (d) Graph the least-squares line. Be sure to plot the point (x, y) as a point on the line. WebAssign Plot WebAssign Plot WebAssign Plot WebAssign Plot (e) Find the value of the coefficient of determination r2. What percentage of the variation in y can be explained by the corresponding variation in x and the least-squares line? What percentage is unexplained? (Round your answer for r2 to three decimal places. Round your answers for the percentages to one decimal place.) r2 = explained % unexplained % (f) At an archaeological site with elevation 6.1 (thousand feet), what does the least-squares equation forecast for y = percentage of culturally unidentified artifacts? (Round your answer to two decimal places.) %

The accompanying data represent the miles per gallon of a random sample of cars with a​ three-cylinder, 1.0 liter engine.

32.4
34.1
34.5
35.7
36.1
36.3
37.5
37.7
37.9
38.1
38.3
38.5
38.7
39.1
39.5
39.8
39.9
40.6
41.3
41.6
42.3
42.7
43.8
49.0

Find the following:

A) 5! =

B) ₇C₂ =

C) ₇P₂ =

Explain how to calculate the NPV (net present value) of an alternative.

What is the decision rule for adopting a project?

Suppose that the average waiting time for a patient at a physician's office is just over 29 minutes. In order to address the issue of long patient wait times, some physicians' offices are using wait-tracking systems to notify patients of expected wait times. Patients can adjust their arrival times based on this information and spend less time in waiting rooms. The following data show wait times (minutes) for a sample of patients at offices that do not have a wait-tracking system and wait times for a sample of patients at offices with a wait-tracking system.

Give a brief discussion, comparing and contrasting unit theory learning curves and cumulative average theory learning curves.  Include a discussion of what the impact might be if you incorrectly used a unit theory curve in lieu of a cumulative average theory curve, and vice versa.

Brothers and sisters: Thirty students in a first-grade class were asked how many siblings they have. Following are the results.

2. A lawyer believes that a certain judge imposes prison sentences for property crimes that are longer than the state average 11.7 months. He randomly selects 36 of the judge’s sentences and obtains mean 13.8 and standard deviation 3.9 months.

a) Test the hypothesis at 1% significance level.

b) Construct a 99% confidence interval for the true average length of sentences im- posed by this judge.

c) Construct a 95% confidence interval for the true average length of sentences im- posed by this judge.

d) Compare the margins of error from b) and c).

The payoff X of a lottery ticket in the Tri-State Pick 3 game is $500 with probability 1/1000 and $0 the rest of the time. Assume the payoffs X and Y are for separate days and are independent from each other.

a. What price should Tri-State charge for a lottery ticket so that they can break even in the long run (average profit =$ 0).

b. Find the mean and standard deviation of the total payoff X+Y.

What price do farmers get for their watermelon crops? In the third week of July, a random sample of 41 farming regions gave a sample mean of x bar = $6.88 per 100 pounds of watermelon. Assume that σ is known to be $1.92 per 100 pounds. (a) Find a 90% confidence interval for the population mean price (per 100 pounds) that farmers in this region get for their watermelon crop (in dollars). What is the margin of error (in dollars)? (For each answer, enter a number. Round your answers to two decimal places.) lower limit $ upper limit $ margin of error $ (b) Find the sample size necessary for a 90% confidence level with maximal error of estimate E = 0.39 for the mean price per 100 pounds of watermelon. (Enter a number. Round up to the nearest whole number.) farming regions (c) A farm brings 15 tons of watermelon to market. Find a 90% confidence interval for the population mean cash value of this crop (in dollars). What is the margin of error (in dollars)? Hint: 1 ton is 2000 pounds. (For each answer, enter a number. Round your answers to two decimal places.) lower limit $ upper limit $ margin of error $

An insurance company has three types of annuity products: indexed annuity, fixed annuity, and variable annuity. You are given:

• None of the customers have both fixed annuity and variable annuity.
• 40% of the customers with fixed annuity also have indexed annuity.
• Half of the customers with two annuity products have variable annuity.
• 60% of the customers have indexed annuity.
• The number of customers who have only the variable annuity is the same as the number of customers who have two annuity products.
• All customers have at least one type of annuity.

Determine the proportion of the customers who only have the indexed annuity.