10.1 Assignment
AP Statistics
A study of chromosome abnormalities and criminality examined data from 4,124 males born in
Copenhagen. Each man was classified as having a criminal record or not, using the registers
maintained in the local police offices. Each was also classified as having the normal male XY
chromosome pair or one of the abnormalities XYY or XXY. Of the 4,096 men with normal
chromosomes 381 had criminal records, while 8 of the 28 men with abnormal chromosomes had
criminal records. Some experts believe chromosome abnormalities are associated with increased
criminality.
1. Do these data lend support to this belief? Perform a significance test to answer this question.
2. Construct and interpret a 95% confidence interval for the difference in proportions.
In the 2001 regular baseball season, the World Series Champion Arizona Diamondbacks played 81
games at home and 81 games away. They won 48 of their home games and 44 of the games played
away. We can consider these games as samples from potentially large populations of games played at
home and away.
3. Find the standard error needed to compute a confidence interval for the difference in the
proportions of home games and away games that would be won by the Diamondbacks.
4. Construct and interpret a 90% confidence interval for the difference between the proportion of
games that the Diamondbacks win at home and the proportion that they win when on the road.
5. Most people think that it is easier to win at home than away. Perform a significance test to
determine whether this is true for the Arizona Diamondbacks.