The manufacturing company in Problem 2.18 also produces electric insulators. If the insulators break when in use, a short circuit is likely to occur. To test the strength of the insulators, destructive testing in high-powered labs is carried out to determine how much force is required to break the insulators. Force is measured by observing how many pounds must be applied to the insulator before it breaks. The force measurements, collected from a sample of 30 insulators and stored in Force, are:

a. Construct a frequency distribution and a percentage distribution.
b. Construct a cumulative percentage distribution.
c. What can you conclude about the strength of the insulators if the company requires a force measurement of at least 1,500 pounds before the insulator breaks?