Taxco, a firm specializing in the preparation of income tax returns, claims the mean refund for customers who received refunds last year was $150. For a random sample of 12 customers who received refunds last year, the mean amount was found to be $125, with a standard deviation of $43. Assuming that the population is approximately normally distributed, and using the 0.10 level in a two-tail test, do these results suggest that Taxco’s assertion may be accurate?
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