When Working for the Brooklyn District Attorney, Investigator Robert Burton

question 25

Essay

$\begin{array} { | l | c | c | c | c | c | c | c | c | c | } \hline \text { Leading Digit } & 1 & 2 & 3 & 4 & 5 & 6 & 7 & 8 & 9 \\\hline \begin{array} { l } \text { Benford's law: } \\\text { distribution of } \\\text { leading digits }\end{array} & 30.1 \% & 17.6 \% & 12.5 \% & 9.7 \% & 7.9 \% & 6.7 \% & 5.8 \% & 5.1 \% & 4.6 \% \\\hline\end{array}$
When working for the Brooklyn District Attorney, investigator Robert Burton analyzed the leading digits of the amounts from 784 checks issued by seven suspect companies. The frequencies were found to be 0,18,0,79,476,180,8,23 , and 0 , and those digits correspond to the leading digits of 1,2,3,4,5,6,7,8 , and 9 , respectively. If the observed frequencies are substantially different from the frequencies expected with Benford's Law, the check amounts appear to result from fraud. Use a 0.05 significance level to test for goodness-of-fit with Benford's Law. Does it appear that the checks are the result of fraud?

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Definitions:

Net Income

Net Income is the total profit of a company after all expenses and taxes have been deducted from revenue.

Variable Costs

Costs that vary in proportion to the level of production or business activity.

Fixed Costs

Expenses that do not change with the amount of goods or services produced over a short period.

Variable Costs

Costs that vary directly with the level of production or service provision.