Exxon is claiming that the cost of a barrel of oil is $50. They sampled 200 barrels of oil. Using a significance level of .05:
Step 4: Formulate the decision rule.
a. Reject H0 if -1.64 > z > 1.64
b. Reject H0 if -196 > z > 1.96
c. Reject H0 if -2.58 > z > 2.58
d. Reject H0 if z > 1.96