A firm specializing in the preparation of income tax returns, claims the mean refund for customers who received refunds last year was R150. For a random sample of 12 customers who received refunds last year, the mean amount was found to be R125, with a standard deviation of R43. The test statistic (rounded off to two decimals) is:   A. T=-2.01 B. Z=-2.01 C. T=2.20 D. T<-2.20

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