personnel, David knows that the variance of teller training time in the Southeast region
is 8, and he wonders if the variance in the Southwest region is the same number. His
staff randomly selected personnel files for 15 tellers in the Southwest Region, and
determined that their mean training time was 25 hours and that the standard deviation
was 4 hours. Assume that teller training time is normally distributed. Using = 0.10, the
appropriate decision is ________.
a) increase the sample size
b) reduce the sample size
c) fail to reject the null hypothesis
d) maintain status quo
e) reject the null hypothesis
Pinky Bauer, Chief Financial Officer of Harrison Haulers, Inc., suspects irregularities in
the payroll system, and orders an inspection of a random sample of vouchers issued
since January 1, 2006. A sample of ten vouchers is randomly selected, without
replacement, from the population of 2,000 vouchers. Each voucher in the sample is
examined for errors and the number of vouchers in the sample with errors is denoted by
x. If 20% of the population of vouchers contain errors, P(x = 0) is _______________.
a) 0.8171
b) 0.1074
c) 0.8926
d) 0.3020
e) 0.2000