Question

Got a Tip? Suppose a waitress keeps track of her tips, as a percentage of the bill, for a random sample of 50 tables. (a) Identify the observational units in this study [ Select] (b) Identify the variable in this study. [ Select] ne Variable in this study (c) Classify the variable type as categorical or quantitative. Quantitative Suppose that, unknown to the waitress, her population mean tip percentage is 15%, with a standard deviation of 4%. (d) According to the Central Limit Theorem, what is the standard deviation of the sampling distribution for the mean tip amount of a random sample of 50 tables? [Select] (e) Between what two values is there a 68% chance that her sample mean tip percentage will fall? Select]

Answer 1

(a) The observational unit is percentage tip. (b) The variable is the number of tables (50). (c) It is a quantitative variable. (d) The standard deviation of the sampling distribution is, (e) The two values can be calculated as; Lower value = Hz – 2.2(02) = 15-20.322 (0.5657) (using z-table) = 15-(0.9945) (0.5657) = 14.437% Upper value = ls + Z22(0) =15+20322 (0.5657) (using z-table) =15+(0.9945) (0.5657) = 15.562% So, there is a 68% chance that her sample mean tip percentage will between 14.437% and 15.562%