(9.7) Most errors in billing insurance providers for health care services involve honest mistakes by patients, physicians, or others involved in the health care system. However, fraud is a serious problem. The National anti-fraud association estimates that approximately $68 billion is lost to fraud each year. When fraud is suspected, and audit of randomly selected billings is often conducted. The selected claims are reviewed by experts, and each claim is classified as allowed or not allowed. The distribution of the amounts of claims are frequently highly skewed, with large number of small claims and small number of large claims. Since simple random sampling would likely be overwhelmed by small claims and would tend to miss the large claims, stratification is often used. Data from an audit that used three strata (small, medium, large) is on excel file BILLINGERRORS. a. Construct the 3x2 table of counts for the data and include the marginal totals. b. Find the percent of claims that were not allowed in each of the three strata. c. To perform a significant test, combine the medium and large strata. Explain why we do this. d. State an appropriate null hypothesis to be tested for these data. e. Perform the significance test and report your test statistic with its degrees of freedom, and the P-value. Significant level a is 0.05. State your conclusions.