In: Statistics and Probability
Suppose you are interested in studying regional differences in crime. You take a random sample of 100 cities in the South, and find a mean crime rate of 55 with a sample varianceof 5.78. A sample of 100 cities in the North has a mean crime rate of 50 with a sample varianceof 6.72.
1. Construct a 95% confidence interval around the difference in crime rates between the population of Southern cities and the population of Northern cities.
2. Interpret, in words, the meaning of this interval.
3. Test the null hypothesis that the mean crime rate for the population of cities in the South is less than (or equal to) the mean crime rate for the population of cities in the North. Use a significance level of .01.
4 .In words, what can you say about the relationship between the two variables in this example? (That is, is the relationship statistically significant?).