I'm attempting my homework for practice of statistics and have answered the 10 questions below as such. It said I received a 5/10 and I'm not sure where I went wrong can anyone give me a hand.

Question 1

- A lawn care company claims that it will completely maintain your yard for an average cost to the customer of $55 per month. A random sample of 20 customers has a sample mean of $60 with a sample standard deviation of $10. What calculator function would you use to conducnt a hypothesis test to determin if there is enough evidence to support the claim that the actual average monthly cost is more than $55 ?

1-prop z-test z-test t-test

1 points

Question 2

- Select the appropriate alternative hypothesis for the problem statement in question 1.

H _{a}: mu<55H _{a}: mu>55H _{a}: mu< or = 55H _{a}: mu> or = 55