The “Bank Robberies: A Statistical Analysis
At the beginning of this chapter, on page 332, we presented summary statistics for data on bank robberies for 5 variables: amount stolen,
number of back staff present, number of customers present, number of bank raiders, and travel time from the bank to the nearest police station.
Theses summary statistics were obtained by 3 researchers for data from a sample of 364 bank raids over a several- year period in the United
Kingdom. For all bank raids in the United Kingdom during the years in question:
Page. 332 table:
Variable Mean Standard Deviation
Amount stolen (lbs. Sterling) 20,330.5 53,510.2
# of bank staff present 5.417 4.336
# of customers present 2.000 3.684
# of bank raiders 1.637 0.971
Travel time, in minutes from bank to the nearest police station 4.557 4.028
a.) Identify and interpret a point estimate for the mean of each of the five aforementioned variables
b.) Find and interpret a 95% confidence interval for the mean amount stolen.
c.) Find and interpret a 95% confidence interval for the mean number of bank staff present at the time of robberies
d.) Determine and interpret a 95% confidence interval for the mean number of customers present at the time of robberies
e.) Determine and interpret 95% confidence interval for the mean number of bank raiders
f.) Obtain and interpret a 95% confidence interval for the mean travel time from the nearest police station to the bank outlet