Answer Happy

MELC 25: computes for the length of the confidence interval MELC 27: solves problems involving sample size determination 1. In an interview held among 38 randomly selected Engineers of a certain firm, the mean salary was found to be Php 21,000 with a standard deviation of Php 3000. Use a 95% confidence to estimate the population mean where the sample came from. 2. Maria wants to study the eating habits of an indigenous tribe. She wants to estimate the population mean to within an error of 0.02 of its true value. Previous studies have revealed a standard deviation of 0.3. Using 95% confidence level, find the sample size n that she needs. 3. A random sample of 42 female students in a certain dorm showed an average weekly expenditure of P750 for snack food, with a standard deviation of P175. Construct a 90% confidence interval for the average amount spent each week on snack foods by female students living in this dormitory, assuming expenditures to be approximately normally distributed.