Please help me out with those question?? It's about math etc.?

Question

The CFO of a company selling computer software through mega stores claims that average monthly profits throught out country will exceed $ 1 billion, with a standard deviation of $0.10 billion. A sample survey of software sales in 36 mega stores revealed an average monthly profit of $1.2 billion. You are asked to test the CFO's claim by examining monthly profits from the sample mega stores using the Z-test."

A).State H0 and H1 for this claim

B). is this a upper tailed, lower tailed or two-tailed test? Why?

C). State the decision rule using= 0.05 significance level.

D) Compute Z-statistic

E). What is the p-value?

F) What is your decision regarding ho? Accept or Reject? Why?

G). What is your conclusion regarding the CFO's claim? Was the claim correct or incorrect.

Answer 1

A) H0: profit = 1 (billion) H1: profit > 1 (billion)

B) upper tailed, because the CEO claims that profits will exceed 1 billion.

C)Z(0.05) = 1.645. Reject H0 if Z(observed) > 1.645

D) Z(observed) = (1.2-1)/[0.1/sqrt(36)] = 0.2/(0.1/6) = 12

E) p-value: P(Z>12) (approx.) = 0

F) Reject H0 because p-value = 0 and 12 > 1.645. *note, you only NEED one condition to reject.

G) Conclude that the evidence supports that avg. monthly profit > 1 billion per month at a significance level of 0.05. This supports the CFO's claim.