O DESCRIPTIVE STATISTICS Approximationg the standard deviation of a data set given a... The Int \\ Revenue Service (IRS) determines which income tax returns to audit by looking at, among other things, whether there are any unusual deductions claimed on the return. Last year, charitable deductions for a family of four earning between $50,000 and $55,000 averaged $1025, with a standard deviation of $150. The IRS wishes to know whether the standard deviation this year is still around $150. To determine this, 40 income tax returns for families of four earning between $50,000 and $55,000 were randomly selected from this year's tax filings. The charitable deductions claimed on the returns are summarized in the following histogram: Frequency 15 12 12 10- 8 5- 4 900 1000 1100 1200 1300 1400 Charitable deduction (in dollars) Based on this histogram, estimate the standard deviation of the sample of 40 deduction amounts. Carry vour intermediate computations to at least four decimal places and round vour answer to at least one decimal place Explanation Check