To assess the accuracy of a lab scale, a standard weight known to weigh 10 grams is weighed repeatedly. The scale readings are normally distributed with unknown mean and the standard deviation of the scale reading is known to be 0.0002 grams. The following procedure could be used to test whether the scale is accurate (i. e., does the reported weight from the scale equal 10 gramsa. The weight is measured 5 times. The mean result is 10.0023 grams. Give a 98% confidence interval for the mean of repeated measurements of the weight. b. How many measurements must be averaged to get a margin of error of ±0.0001 with 98% confidence?

Martha has a deck of cards. she has lost some of the cards, and now the deck only contains nine spades, eleven diamonds, eight clubs, and twelve hearts. martha predicts that whenever she draws a card from the deck without looking, she will draw a club one-fifth of the time. which activity would best allow martha to test her prediction? a. randomly draw a card from the box and see if it is a club. b. randomly draw a card. then, continue to draw another card until all eight clubs are drawn. c. randomly draw and replace a card 120 times. then, observe how close to 30 times a club is drawn. d. randomly draw and replace a card 100 times. then, observe how close to 20 times a club is drawn.