need help with the following

The range for a set of data is estimated to be 44. (a) What is the planning value for the population standard deviation? (b) At 95% confidence, how large a sample would provide a margin of error of 3? (Round your answer up to the nearest whole number.) (c) At 95% confidence, how large a sample would provide a margin of error of 2? (Round your answer up to the nearest whole number.)The U.S. Energy Information Administration (US EIA) reported that the average price for a liter of regular gasoline is $0.78. The US EIA updates its estimates of average gas prices on a weekly basis. Assume the standard deviation is $0.09 for the price ofa liter of regular gasoline and recommend the appropriate sample size for the US EA to use if they wish to report each of the following margins of error at 95% condence. (Round your answers up to the nearest whole number.) (a) The desired margin of error is $0.04. (b) The desired margin of error ls $0.03. (c) The desired margin of error is $0.02