An office manager has received a report from a consultant that includes a section on equipment
replacement. The report indicates that scanners have a service life that is normally distributed
with a mean of 41 months and a standard deviation of 4 months. On the basis of this information,
determine the percentage of scanners that can be expected to fail in the following time periods:
a. Before 38 months of service
b. Between 40 and 45 months of service
c. Within ±2 months of the mean life