A cellular phone company advertises that the average age of its

2. If n = 25 and α = .05 in a right-tailed test of a mean with unknown σ, the critical value is: .0179  1.645  1.711  1.960

3. The process that produces Sonora Bars (a type of candy) is intended to produce bars with a mean weight of 56 gm. The process standard deviation is known to be 0.77 gm. A random sample of 49 candy bars yields a mean weight of 55.82 gm. Which are the hypotheses to test whether the mean is smaller than it is supposed to be?

H0: μ < 56, H1: μ ≥ 56H0: μ ≥ 56, H1: μ < 56H0: μ = 56, H1: μ ≠ 56H0: μ ≤ 56, H1: μ > 56

4.To estimate the average annual expenses of students on books and class materials a sample of size 36 is taken. The sample mean is $850 and the sample standard deviation is $54. A 99 percent confidence interval for the population mean is: $826.82 to $873.18 

$825.48 to $874.52 

$832.36 to $867.64 

$823.72 to $876.28

5. If SSE is near zero in a regression, the statistician will conclude that the proposed model probably has too poor a fit to be useful. True False