1. A random sample of hot dogs of a particular brand has an average fat content of 20 grams and standard deviation of 3. How large a sample should be taken so that the sample average is within 0.25 gram of the true average with confidence level 96%?

2. A random sample of size 24 is obtained from a normal population. Find the critical values of 2Left and 2Right for 90% confidence level

3. In a random sample of 80 male students in a school, the average height is 68.2 inches with a standard deviation 4.5 inches. Obtain a 73% confidence interval for the mean height of all the male students in the school.

Provide me detailed solution with explanation please