problems 1 - 5: A manufacturer of paper is interested in improving the product's tensile strength. Engineers believe that tensile strength is a function of hardwood concentration in the pulp. There are four possible levels of this concentration. They decide to check specimens at each concentration level. The tensile strengths in the following table are given in psi:

Concentration 1	7, 8, 15, 11, 9, 10
Concentration 2	12, 17, 13, 18, 19, 15
Concentration 3	14, 18, 19, 17, 16, 18
Concentration 4	19, 25, 22, 23, 18, 20

1. Using your calculator, compute all sums of squares and determine all degrees of freedoms.

1. Using your calculator, compute all mean squares.

1. Check and see whether conditions for ANOVA are satisfied. For homogeneity of variances, you may use any one of the three methods.

1. Conduct the appropriate hypothesis test.

1. If needed, construct confidence intervals for pairs of variables.

Use this information for problems 6 - 10: Researchers have sought to examine the effect of various types of music on agitation levels in patients who are in the early and middle stages of Alzheimer's disease. Patients were selected to participate in the study based on their stage of Alzheimer's disease. Three forms of music were tested: Easy listening, Mozart, and piano interludes. While listening to music, agitation levels were recorded for the patients with a high score indicating a higher level of agitation. Scores are recorded below.

Group	Piano Interlude	Mozart	Easy Listening
Early Stage Alzheimer's	21 24 22 18 20	9 12 10 5 9	29 26 30 24 26
Middle Stage Alzheimer's	22 20 25 18 20	14 18 11 9 13	15 18 20 13 19

1. Run the diagnostic tests for normality and constant variance.

1. Find the sum of squares, corresponding degrees of freedom, and mean squares. What is