To assess the accuracy of a laboratory scale, a standard weightknown to weigh 10 grams is weighed repeatedly. The scale readingsare normally distributed with unknown mean (this mean is 10 gramsif the scale has no bias). The standard deviation of the scalereadings is known to be 0.0003 gram.
(a) The weight is measured three times. The mean result is10.0023 grams. Give a 98% confidence interval for the mean ofrepeated measurements of the weight. (Round your answers to fourdecimal places.)
(b) How many measurements must be averaged to get a margin oferror of ±0.0001 with 98% confidence? (Round your answer up to thenearest whole number.)
