6. Select correct response (8 points, 1 point each)

1)Using the information given below,

2-Sample t-test and Confidence Interval

2-sample t for Group 1 vs. Group 2

NMeanStDevSE Mean

Group 120109.258.271.9

Group 220108.510.42.3

-level: 0.05;95% CI for mu Group 1 - mu Group 2: ( -5.3,6.8)

t-test mu Group 1 = mu Group 2 (vs. not =): t-value = 0.25

P-value= 0.80DF = 36

a.we would reject the null hypothesis that the mean of Group 1 is equal to the mean of Group 2?

b.we would fail to reject the null hypothesis that the mean of Group 1 is equal to the mean of Group 2?

c.Both a & b

d.None of the above

2) The "p-value " in hypothesis test is:

a.The risk of making a Type II error.

b.The risk of accepting a false null hypothesis.

c.The probability that is based on observed value of test statistic

d.Often called the consumer's risk

3)The Human Resources department wants to compare the average weekly pay for welders to the average weekly pay for operators.Based on the 2-sample t test results shown below, what is your conclusion?

2-Sample t-test and CI: Welders, Operators

2-Sample t for Welders vs. Operators

NMeanStDevSE Mean

Welders21403.541.99.1

Operator21375.023.95.2

Difference = mu Welders - mu Operators

Estimate for difference:28.5

-level: 0.05

95% CI for difference: (7.1, 50.0)

t-test of difference = 0 (vs. not =): t-value = 2.71p-value = 0.011

a.There is no difference in weekly pay for welders and operators

b.Welders are paid more on average than operators

c.Operators are paid more on average than welders

d.There is not enough data to make a decision

4) Ten samples were drawn from two processes A & B.The sample averages(Xbar-_A& Xbar-_B) were calculated for each process.We are trying to determine if there is a difference in the mean of the two processes.

What would be an appropriate null hypothesis, H₀?

a.Ho: The two sample variances are the same

b.Ho: The mean of process A is the same as the mean of process B

c.Ho: The mean of process A is not the same as the mean of process B

d.Ho: The two sample variances are not the same.

5) The "-level" or "significance level" is:

a.The risk of making a Type II error.

b.The risk of accepting a false null hypothesis.

c.The risk of rejecting a true null hypothesis.

d.Often called the consumer's risk

6. Please use the ANOVA results below:

One-way Analysis of Variance

Analysis of Variance

SourceDFSSMSFP

Factor412253063.020.022

Error959650102

Total9910875

LevelNMeanStDev

Group 12099.408.70

Group 220100.2911.98

Group 32096.6910.31

Group 420106.4810.06

Group 52097.199.00

What can we say about the results of the ANOVA: (at-levelof0.05)?

a.At least one of the means is significantly different.

b.There are no significant differences among the five group means.

c.We can't tell from this analysis.

d.The sample sizes are too small to determine significance. We need more data.