A clinical trial was conducted to test the effectiveness of a drug for treating insomnia in older subjects. Before​ treatment, 19 subjects had a mean wake time of 105.0 min. After​ treatment, the 19 subjects had a mean wake time of 99.4 min and a standard deviation of 21.9 min. Assume that the 19 sample values appear to be from a normally distributed population and construct a 95​% confidence interval estimate of the mean wake time for a population with drug treatments. What does the result suggest about the mean wake time of 105.0 min before the​ treatment? Does the drug appear to be​ effective?

PART 2:

What does the result suggest about the mean wake time of 105.0 min before the​ treatment? Does the drug appear to be​ effective? The confidence interval_____ includes

does not include the mean wake time of 105.0 min before the​ treatment, so the means before and after the treatment _______ are different. could be the same. This result suggests that the drug treatment ________. does not have has a significant effect.

When subjects were treated with a​ drug, their systolic blood pressure readings​ (in mm​ Hg) were measured before and after the drug was taken. The results are given in the table below. Assume that the paired sample data is a simple random sample and that the differences have a distribution that is approximately normal. Using a 0.050 significance​ level, is there sufficient evidence to support the claim that the drug is effective in lowering systolic blood​ pressure?

Before: 205 159 208 195 205 210 207 157 189 167 164 169

After: 176 163 183 176 143 179 189 152 155 177 148 186

In this​ example, Md is the mean value of the differences d for the population of all pairs of​ data, where each individual difference d is defined as the systolic blood pressure reading before the drug was taken minus the reading after the drug was taken. What are the null and alternative hypotheses for the hypothesis​ test?

Thank you in advance.

In 1995 the Mars Company replaced tan M&Ms with blue M&Ms. A sample of 100 plain M&Ms before the introduction of blue M&Ms had a mean weight 0.9160g with a standard deviation of 0.0433g. A sample of 100 plain M&Ms taken after 1995 had a mean weight of 0.9147g and a standard deviation of 0.0369g. (a) Construct the 98% confidence interval for the difference in the mean weight of plain M&Ms before and after the introduction of blue M&Ms. List: Parameters: u1 and u2 Null and Alt. Hypothesis p-value Initial conclusion Final conclusion (b) Is there a significant difference between mean weight of plain M&Ms before and after the introduction of blue? How do you know? List: t* ME Interval Interpret Interval (c) Does the confidence interval support the results of the hypothesis test? Why or why not?

Suppose data were collected on the number of customers that frequented a grocery stores on randomly selected days before and after the governor of the state declared a lock down due to COVID 19. A sample of 6 days before the lockdown were chosen as well as 6 days randomly chosen after the lock down was in place. The number of shoppers each day were as follows:

This is interval/ratio data because they are characteristics of the days.

1. Can these results be generalized? To whom?
2. Can cause and effect statements be made? Explain.
3. Calculate accountable, unaccountable, and total variation. Show your work.
4. Eta square is accountable variation divided by total variation. Determine eta square. It is interpreted as the variation in the dependent variable that can be accounted for by the independent variable. Describe eta square in terms of this problem.

1. A standardized test has a scale that ranges from 3 to 45. A new type of review course for the. test was developed by a training company. The accompanying table shows the scores for nine students before and after taking the review course. Use 0.01 significance level to determine if the average test score is higher for the students after the review course when compared with before the course.

iv. Make a decision to reject or fail to reject the Ho. (1 Mark)

v. Interpret the decision in the context of the original claim.

Assume that you have the following information:-

Market Info:- Real interest rate = 2.0%; Expected inflation = 4.0%; Rm = 12.0%; Tax = 30.0%.

Com. Stock info:- Par value = $1.0 ; Market value (price) = ?? ; Beta = 1.60 ; No. of outstanding shares = 1,000,000.0 ; EPS $3.0 ; pay-out ratio = 30.0%;

Growth in EPS & Dividends = 5.0% ;

Preferred Stock info:- Par value = $100.0; Dividend per share = 10.0%; Rp=8.0%; No. of outstanding shares = 100,000.0; Price = ????

Bonds info:- Par value = $1,000.0; Coupon interest = 4.0% ; YTM = 6.0%; Time to maturity = 20 years ; No. of bonds = 100.0; Price = ???

1- Calculate the WACC using historical weights in the capital structure.

2 - Calculate the WACC using market weights in the capital structure.

3 - The before and after tax cost of debt.

4 -The before and after tax cost of equity.

5 - The before and after tax cost of preferred stock.

A study looked at number of cavity children per 100 in 18 North American cites before and after public water fluoridation projects. The following table lists the data.

a. Please test whether there is a significant change in number of cavity children per 100 after and before public water fluoridation. Make sure you include all the five steps in the hypothesis testing questions.

b. What is the 95% confidence interval for the change?

A manager wishes to see if the time (in minutes) it takes for their workers to complete a certain task is different if they are wearing earbuds.   A random sample of 20 workers' times were collected before and after wearing earbuds. Test the claim that the time to complete the task will be different, i.e. meaning has production differed at all, at a significance level of α = 0.01

For the context of this problem, μ_D = μ_before−μ_after where the first data set represents before earbuds and the second data set represents the after earbuds. Assume the population is normally distributed. The hypotheses are:

H₀: μ_D = 0
H₁: μ_D  0

Before

After

69

65.3

69.5

61.6

39.3

21.4

66.7

60.4

38.3

46.9

85.9

76.6

70.3

77.1

59.8

51.3

72.1

69

79

83

61.7

58.8

55.9

44.7

56.8

50.6

71

63.4

80.6

68.9

59.8

35.5

73.1

77

49.9

38.4

56.2

55.4

64.3

55.6

The Levy Box plant produces wooden packing boxes to be used in the local seafood industry. Current operations allow the company to make 600 boxes per day, in two 8-hour shifts (300 boxes per shift). The company has introduced some moderate changes in equipment, and conducted appropriate job training, so that production levels have risen to 400 boxes per shift. Labor costs average $13 per hour for each of the 5 full-time workers on each shift. Capital costs were previously $4,000 per day, and rose to $4,200 per day with the equipment modifications. Energy costs were unchanged by the modifications, at $400 per day.

a) What is the firm's multifactor productivity (exhibit 2.5) before and after the changes?

b) What is the firm's labor hours productivity before and after the changes?

c) What is the percent change in the multifactor productivity before and after the changes?

A pharmaceutical company claims that its new drug reduces systolic blood pressure. The systolic blood pressure (in millimeters of mercury) for nine patients before taking the new drug and 2 hours after taking the drug are shown in the table below. Using this data, find the 99% confidence interval for the true difference in blood pressure for each patient after taking the new drug. Assume that the blood pressures are normally distributed for the population of patients both before and after taking the new drug.

Copy Data

Step 1 of 4:

Find the point estimate for the population mean of the paired differences. Let x1 be the blood pressure before taking the new drug and xx2 be the blood pressure after taking the new drug and use the formula d=x2−x1 to calculate the paired differences. Round your answer to one decimal place.

Step 2 of 4:

Calculate the sample standard deviation of the paired differences. Round your answer to six decimal places.

Step 3 of 4:

Calculate the margin of error to be used in constructing the confidence interval. Round your answer to six decimal places.

Step 4 of 4:

Construct the 99% confidence interval. Round your answers to one decimal place.