Which of the following statements iscorrect?

a.An interval estimate describes a range of values that is likely not to include the actual population parameter

b.An interval estimate is an estimate of the range for a sample statistic

c.An interval estimate is an estimate of the range of possible values for a populationparameter

d.All of the above

The sales representative for a manufacturer of a new product claims that the product will increase output per machine by at least 29 units per hour.A line manager installs the product on 15 of the machines, and finds that the average increase was only 26 with a standard deviation of 6.2. What are the appropriate null and alternative hypotheses?

a.H0:= 29H1: 29

b.H0: 29H1:< 29

c.H0: = 29H1: > 29

d.H0: > 29H1: 29

The sales representative for a manufacturer of a new product claims that the product will increase output per machine by at least 29 units per hour.A line manager installs the product on 15 of the machines, and finds that the average increase was only 26 with a standard deviation of 6.2. Using a 5 % significance level, which of the following statements is true?

a.Reject H0iftstatistic < 1.761

b.Reject H0iftstatistic>2.16

c.Reject H0iftstatistic <-1.761

d.Reject H0iftstatistic < -2.16

Two samples each of size 20 are taken from independent populations assumed to be normally distributed with equal variances. The first sample has a mean of 43.5 and standard deviation of 4.1 while the second sample has a mean of 40.1 and standard deviation of 3.2. A researcher would like to test if there is a difference between the population means at the 0.05 significance level.What is the pooled variance?

a.3.650

b.5.201

c.13.525

d.none of above

Two samples each of size 20 are taken from independent populations assumed to be normally distributed with equal variances. The first sample has a mean of 43.5 and standard deviation of 4.1 while the second sample has a mean of 40.1 and standard deviation of 3.2. A researcher would like to test if there is a difference between the population means at the 0.05 significance level.What is the value of the test statistic?

a.2.92

b.0.79

c.3.62

d.1.74

Two samples each of size 20 are taken from independent populations assumed to be normally distributed with equal variances. The first sample has a mean of 43.5 and standard deviation of 4.1 while the second sample has a mean of 40.1 and standard deviation of 3.2. A researcher would like to test if there is a difference between the population means at the 0.05 significance level.What can the researcher conclude?

a.There is not sufficient evidence to reject the null hypothesis; the population means and standard deviations are equal

b.There is no reason to conclude that the two population means are equal

c.There is sufficient evidence to reject the null hypothesis and conclude that the two population means are different

d.The answer cannot be determined without calculating thep-value and comparing it to the significance level