Statistics Class Classwork for 9/27/2011

STATISTICS CLASS – CLASSWORK FOR 9/27/2011

READ, CONSIDER THE FOLLOWING AND WRITE:

1. SPACE SHUTTLE CHALLENGER DISASTER – JANUARY 28, 1986

73 seconds into its flight, the space shuttle exploded due to faulty o-rings. Exactly what mistake did the NASA engineers make? Write up to 200 words on what mistake the engineers made and how it relates to statistics class (you will probably need to research this).

2. The following table shows the number of hits and 'at bats' for Derek Jeter and David Justice for 1995, 1996 and those years combined.

1995 1996 Combined Batter # Hits # At Bats # Hits # At Bats # Hits # At Bats Derek Jeter 12 48 183 582 195 630 David Justice 104 411 45 140 149 551

a. Calculate the batting average (# hits / # at bats) for 1995 and 1996 for Jeter and Justice. Who did better? b. Now calculate the combined years batting average for both. Who did better? a. What's going on?

3. The results from a large survey were published in the American Statistician, 50, pp. 340- 3411 (1996). 1314 women were surveyed and asked if they smoked. Twenty years later, the women were again contacted and determined if they were dead or alive. The data is summarized as follows:

The 'Odds of Death' ratio is the number dead divided by the total for that particular Smoking Status ( e.g. Smoking Status 'Yes', Odds of Death = 139/443=0.314). These are the genuine results of the study. a. Clearly, those who did not smoke died more over the twenty year period. Why do think that is? a. More information is provide on the table below.

Use this information to help explain the misinformation of the previous table.