statistics and Probability

Ill Directions: Solve the problem below. Martina reads that the average age of graduate students is 33 years old. She wanted to estimate the mean age of the graduate students at her university, so she took a random sample of 30 graduate students. She found that their mean age was *=31.8 at a 95 % confidence level with 1.54 margin of error. Questions: 1. What is the lower limit? 2. What is the upper limit? 3. What is the confidence interval? 4. Based on the interval you get, is it plausible that the mean age of all graduate students at her university is also 33 years