A manufacturing company produces electric insulators. You define the variable of interest as the strength of the insulators. If the insulators break when in use, a short circuit is likely. To test the strength of the insulators, you carry out destructive testing to determine how much force is required to break the insulators. You measure force by observing how many pounds are applied to the insulator before it breaks. The data shown below represent the amount of force required to break a sample of 30 insulators. Complete parts a through c below. 2 7 10 8 16 20 15 27 18 29 0 22 28 21 21 28 26 25 25 40 60 2 45 41 16 20 22 20 18 34 a. Construct a 90% confidence interval for the population mean force. us (Round to two decimal places as needed.)