the average for licnesed drivers in the country is an average of 42.6 yrs with a standard deviation of 12. The distribution is approx... normal.
a. a researcher obtained a sample of n=36 drivers who received parking tickets. The average age for these drivers was m= 40.7. Is this a reasonable outcome for a sample of n=36 or is this sample mean an extreme value?
b. The same researcher also obtained a sample of n-16. drivers who received speeding tickets. The average for this sample was M=34.4. Is this a reasonable outcome for a sample of n=16 or is the sample mean very different from what would usually be expected? (compute the z-score for the sample mean)