A recent study was conducted by X Company to determine if there was a difference in humor content in coal and natural gas trade magazine ads. In an independent random sample of 400 coal trade ads, 81 were humorous. An independent random sample of 330 natural gas ads contained 50 humorous ads. Test at alpha=.02 to determine if there is a difference in the proportion of humorous ads in the two industries.
a) Formulate the appropriate hypothesis
b) Write the decision rule
c) Find the test statistic value
d) Give your conclusion
e) Tell if/how the test helps you in determining which loader to purchase.