Q1) Company claims that 9 out of 10 doctors (i.e., 90%) suggest its brand of cough syrup to their patients. To test this claim against alternative that actual proportion is less than 90%, a random sample of doctors was taken. Assume the test statistic is z = -1.75. Can we conclude that H0 must be rejected at the a) α = .10, b) α = .05, and c) α = .01 level?

i) no; b) no; c) yes

ii) no; b) no; c) no

iii) yes; b) yes; c) no

iv) yes; b) yes; c) yes

Q2) A __________ is numerical quantity calculated from data of a sample and is used in reaching a decision on whether or not to reject null hypothesis.

a) Parameter

b) Test statistic

c) Critical value

d) Significance level

Q3) How many tissues must a package of tissues contain? Researchers have find out that a person uses the average of 48 tissues during a cold. Assume a random sample of 100 people yielded following data on number of tissues utilized in a cold: x-bar = 38, s = 20. By using sample information provided, compute the value of test statistic for the relevant hypothesis test.

a) 0

b) -5

c) 5

d) 1

Q4) We have created 95% confidence interval for m with result (9, 14). What conclusion will we make if we test H0: μ = 18 vs. Ha: μ ≠ 18 at a = .05?

i) Reject H0 in favor of Ha.

ii) We cannot tell what our decision will be with the information given.

iii) Fail to reject H0.

iv) Accept H0 rather than Ha.

Q5) National organization has been working with utilities all through nation to find sites for large wind machines which generate electricity. Wind speeds should average more than 22 miles per hour (mph) for a site to be acceptable. Recently, organization conducted wind speed tests at particular site. Based on sample of n = 47 wind speed recordings (taken at random intervals), wind speed at site averaged x-bar = 22.6 mph, with standard deviation of s = 4 mph. To find out whether site meets organization's needs, consider test, H0: μ = 22 vs. Ha: μ > 22, where μ is true mean wind speed at site and α = .01. Assume value of test statistic were calculated to be 1.03. State conclusion.

a) We are 99% confident that site meets organization's requirements.

b) At α = .01, there is enough evidence to conclude true mean wind speed at site exceeds 22 mph.

c) At α = .01, there is inadequate evidence to conclude true mean wind speed at the site exceeds 22 mph.

d) We are 99% confident that site doesn't meet organization's requirements.

Q6) Given H₀: μ = 18, H_a: μ < 18, and p = 0.066. Do you reject or fail to reject H₀ at.05 level of significance?

a) Reject H0.

b) Not sufficient information to decide.

c) Fail to reject H0.