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Taxes: The Internal Revenue Service reports that the mean federal income tax paid in the year 2010 was $8040. Assume that the standard deviation is $4800. The IRS plans to draw a sample of 1000 tax returns to study the effect of a new tax law. Part 1 of 5 (a) What is the probability that the sample mean tax is less than $ 8200? Round the answer to at least four decimal places. The probability that the sample mean tax is less than $8200 is Part 2 of 5 (b) What is the probability that the sample mean tax is between $ 7400 and $7900? Round the answer to at least four decimal places. The probability that the sample mean tax is between $7400 and $7900 is