i have the solution but need better explanation in excel if possible

An urban economist wishes to estimate the mean amount of time people spend travelling to work. He obtains a random sample of 60 individuals who are in the labour force and nds that the mean travel time is 30.5 minutes. Assuming that the population standard deviation of travel time is 20.5 minutes. construct and intert a 90% condence interval for the mean travel time to work. (Note: the standard deviation is large. because some people work at home and thus travel 0 minutes and some people take transit which results in large travel times]. Show the complete solution in the space provided. It you used Excel, show all functions used with all the parameters