PLEASE HELP! I don't understand this homework due tomorrow!

A random sample of 10 houses in a particular area, each of which is heated with natural gas, is selected and the amount of gas (in therms) used during the month of January is determined for each house. The resulting observations are as follows:

103, 156, 118, 89, 125, 147, 122, 109, 138, 99

a.Let μj denote the average gas usage during January by all houses in this area. Compute a point estimate of μj.

b.Suppose that 10,000 houses in this area use natural gas for heating. Let τ denote the total amount of gas used by all of these houses during January. Estimate τ using the given data. What statistic did you use in computing your estimate?

c.Use the given data to estimate π, the proportion of all houses that used at least 100 therms.

d.Give a point estimate of the population median usage based on the given sample. Which statistic did you use?

Thanks for the help!