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solve for all the parts A study of the ability of individuals to walk in a strai

ID: 2908530 • Letter: S

Question

solve for all the parts

A study of the ability of individuals to walk in a straight line reported the accompanying data on cadence (strides per second) for a sample of n 20 randomly selected healthy men. 0.95 0.85 0.92 0.95 0.93 0.86 1.00 0.92 0.85 0.81 0.76 0.93 0.93 1.04 0.93 1.06 1.06 0.96 0.81 0.97 A normal probability plot gives substantial support to the assumption that the population distribution of cadence is approximately normal. A descriptive summary of the data from Minitab follows. TrMean SEMearn 20 0.9245 0.9300 0.9261 0.0824 0.0184 Variable cadence Variable cadence Mean Median StDev Min 0.7600 1.0600 0.8550 0.9650 Max 01 (a) Calculate and interpret a 95% confidence interval for population mean cadence. (Round your answers to four decimal places.) strides per second Interpret this interval with 95% confidence, the value of the true mean cadence of all such men falls below the confidence interval. with 95% confidence, the value of the true mean cadence of all such men falls within the confidence interval. with 95% confidence, the value of the true mean cadence of all such men falls above the confidence interval The probability the true mean cadence is within this interval is 0.95 You may need to use the appropriate table in the Appendix of Tables to answer this question.

Explanation / Answer

Solution :

(a) Fron the given data mean x-bar = 0.9245 , standard deviation s = 0.0824 , n = 20

=> df = n - 1 = 20 - 1 = 19

=> for 95% confidence interval , t = 2.093

=> For 95% confidence interval for population mean cadence is

=> x-bar +/- t*s/sqrt(n)

=> 0.9245 +/- 2.093*0.0824/sqrt(20)

=> (0.8859 , 0.9631)