I need this question answered within 2 hours, please provide as much detail as possible so i understand it: The average price of homes sold in the

I need this question answered within 2 hours, please provide as much detail as possible so i understand it:

The average price of homes sold in the medium size city in Canada in the past year was $220,000. A random sample of 81 homes sold this year showed an average price of $210,000 with a sample standard deviation of $36,000. Determine whether there has been a significant decrease in the average price of homes.

1. State the null and alternative hypotheses to be tested. 
2. Compute the test statistic. 
3. Determine the critical value for this test at the 0.05 level of significance. 
4. What do you conclude?
5. Construct a 95% confidence interval for the average price of homes sold this year.