1. Find out the critical value for the one-tailed hypothesis test in which a null hypothesis is tested at 5% level of significance based upon a sample size of 25?

2. A large department store analyzed a sample of 18 credit card sales and recorded amounts charged for each of three kinds of credit cards: MasterCard, Visa and Discover. Six MasterCard sales, seven Visa and five Discover sales were recorded. The store employed ANOVA to test if the mean sales for each credit card were equal. What are the degrees of the freedom for F statistic?

3. If the critical z-value for test statistic equals 2.45, find out the value of the test statistic would guarantee no chance of making Type I error?

4. What is our decision for goodness-of-fit test with the evaluated value of chi-square of 1.273 and critical value of 13.388?

5. A manufacturer wants to raise the absorption capacity of sponge. Based upon past data, the average sponge could absorb 3.5 ounces. After redesign, the absorption amounts of sample of sponges were (in ounces): 4.1, 3.7, 3.3, 3.5, 3.8, 3.9, 3.6, 3.8, 4.0, and 3.9. What is the decision rule at 0.01 level of significance to test if the new design raised the absorption amount of sponge?

6. Two chi-square distributions were plotted on same chart. One distribution was for three degrees of freedom and other was for 12 degrees of freedom. Which distribution would tend to approach the normal distribution?