4. A random sample of size 16 songs has been selected from a normally distributed population. If the mean value of length is 140 seconds and the length varies from 110 to 160, find the error for 90% confidence interval

5. A simple random sample of the ages of 80 actresses when they won Oscars was withdrawn from a normal population with standard deviation =11.1 years. If the sample mean average is x=35.9 years, use =0.01 significance level to test the claim that the mean age of actresses when they win Oscars is more than 33 years. Use both methods: z-stat and p-value.

Provide me detailed solution with explanation please