Of 58 bank customers depositing a check, 15 received some cash back. to} Construct a 90 percent confidence interval for the proportion of all depositors who ask for cash back. {Round your answers to 4 decimal plat-55.} The 90% confidence interval is from | to | (b) May normality of p be assumed? Cl Yes O No Use the sample information 5: = 43, = 3, n = '11 to calculate the following condence intervals for ,1! assuming the sample is from a normal population. la} 90 percent condence. (Round your answers to 4 decimal places.} The 90% confidence interval is from |to lb} 95 percent confidence. {Round your answers to 4 decimal places} The 95% confidence interval is from | to [c199 percent condence. (Round your answers to 4 decimal places} The 99% confidence interval is from to id} Describe how the intervals change as you increase the condence level. O The interval gets narrower as the condence level increases. 0 "he interval gets wider as the condence level decreases. 0 "he interval gets wider as the condence level increases. O The interval stays the same as the condence level increases. The Ball Corporation's beverage can manufacturing plant in Fort Atkinson, Wisconsin, uses a metal supplier that provides metal with a known thickness standard deviation 0: .000672 mm. Assume a random sample of 56 sheets of metal resulted in an :E = .2737 mm. Calculate the 98 percent confidence interval for the true nean metal thickness. [Round your answers to 4 decimal places.) The 98% condence interval is from | to | A random sample of 27 items is drawn from a population whose standard deviation is unknown. The sample mean is i = 940 and the sample standard deviation is S: 15. Use Appendix D to nd the values of Student's t [a] Construct an interval estimate ofp with 99% confidence. {Round your answers 1.0 3 decimal places.) The 99% confidence interval is from to lb} Construct an interval estimate ofpw'rth 99% confidence, assuming that s = 30. {Round your answers to 3 decimal places.) The 99% confidence interval is from to (c) Construct an interval estimate oft} with 99% condence, assuming that s = 60. {Round your answers to 3 decimal places.) The 99% confidence interval is from to id} Describe how the condence interval changes as s increases. 0 "he interval stays the same as s increases. 0 "he interval gets wider as 5 increases. 0 "he interval gets narrower as s increases. A random sample of 16 pharmacy customers showed the waiting times below On minutes). 15 12 17 19 23 14 Click here forthe Excel Data File 17 25 Find a 90 percent condence interval for p, assu answer to 4 decimal places and t-value to 3 decimal places. Round your answers to 3 decimal places} 14 16 17 22 1? 12 1? 18 'ning that the sample is from a normal population. {Round your standard deviation The 90% confidence interval to| Calculate the standard error. May normality be assumed? [Round your answers to 4 decimal placesJ Standard Error Normality (a) n = 25, SIT = .56 (Click to select]v (b) n = 5+3, :7 = 42 (Click toselectlv (c) n = 93, if = 41 (Click to selecv (d) n = 485, I = .664 (Click to select}v
