How to solve these problems?Thank you

Homework on confidence intervals for mean and proportions 1, Confidence interval for the mean, large sample Givena sample of n = 75 TVsets have a mean life time of 8:2years and a standard deviation of Ill years .. as find the best point estimate of the population clan 4) Find a 90% confidence interval for the near life of all TV's (assuming the sample S. D. is equal to the population SD) answers as 8 12 2 ) ( 8 . 0 , 8. 4 ) 2. Sample size problem How large a sample to needed tobe 952 .. fill the mean is withinal 5 minutes mang In of error, assunny all standard deviation of 90 minutes (answer 131) Confidence interval for a proportion 3 , In a random sample of n - 785 , It was found that 1813 % had visited an art Museum Construction 95 %% confidence interval for the proportion of all peoplewho visited an art museum arsi ( 1 157, , 215 or 15,1%, 21.5 %% ), a point echmals would be, 183 ar 19,31