I'm lost, so I'd greatly appreciate as much detail as possible. Thank you!

4. 4. Cylindrical (metal) pins having mean length of 14.8 cm are manufactured with standard deviation of 0.6 cm. For a specific application, it is necessary to supply rods that are at least 13.2 cm long. a) What is the probability that any given rod will be under the required length specification? b) Determine the sample size that is required to specify that the length for a given production run is within 10.46 cm at a confidence level of 99%