21. The volumes of soda in quart soda bottles can be described by a normal model with a mean of 27 oz and a standard deviation of 2 oz. A bot 26.5 oz., calculate a z-score. z = a. 0.25 b. 0.50 C. -0.25 d. -0.50 22. A nationwide survey shows that football players have a mean weight of 256 pounds and a standard deviation of 27 pounds. For a randomly chosen player, what is the probability that his weight is 298 pounds or less? z = = a. 0.9332 b. 0.9406 0.00 0.01 0.02 0.03 0.04 0.05 0.06 c. 0.9452 d. 0.0594 1.5 0.9332 0.9345 0.9357 0.9370 0.9382 0.9394 0.9406 1.6 0.9452 0.9463 0.9474 0.9484 0.9495 . 0.9505 0.9515 23. A bank took a sample of 100 of its delinquent credit card accounts and found that the mean owed on these accounts was $2,130. The popul standard deviation for these delinquent accounts is $578. Determine a 95% confidence interval for the mean amount owed on all delinquent credit card accounts for this bank. CI = x + za/2 () a. ( 2017, 2243) b. ( 2,030, 2230) onfidence Level za/ , 90% 1.645 c. (1552, 2708) d. (2037, 2285) 95% 1.96 99% 2.575