solve the following problems

SOLVE THE PROBLEMS: 1. A government agency was changed by legislature with estimating the length of time it takes citizens to fill out various form. Two hundred randomly selected adults were timed as they filled out a particular form. The times required had mean 12.8 minutes with standard deviation 1.7 minutes. Construct a 90% confidence interval for the mean time taken for all adults to fill out this form. 2. A sample of 250 workers aged 16 and older produced an average length of time with the current employer of 4.4 years with standard deviation of 3.8 years. Construct a 99.9% confidence interval for mean job tenure of all workers aged 16 or older. 3. A corporation that own apartment complexes wishes to estimate the average length of time residents remain in the same apartment before moving out . A sample of 150 rental contracts gave a mean length of occupancy of 3.7 with standard deviation of 1.2 years. Construct a 95% confidence interval for the mean length of occupancy of apartments own by corporation. 4. In order to estimate the mean amount of damage sustained by vehicles when a cow is struck, an insurance company examined the records of 50 such occurrences, and obtained a sample mean of Php2,785 with standard deviation of Php221. Construct a 95% confidence interval for the mean amount of damage in all such accidents