Answered: SmithTelecome is a supplier to many…

MATLAB: An Introduction with Applications

6th Edition

ISBN:9781119256830

Author:Amos Gilat

Publisher:Amos Gilat

Chapter1: Starting With Matlab

Section: Chapter Questions

Problem 1P

See similar textbooks

Related questions

Question

SmithTelecome is a supplier to many brand-name makers of mobile phones. SmithTelecome manufactures the external shells that enclose mobile phones. The strength of a shell is measured by applying increasing pressure to the shell and recording the pressure at which the shell breaks. Shell strengths are approximately normally distributed. A random sample of 50 shells made by SmithTelecome showed an average strength of 30.0 pounds and a (sample) standard deviation of 5.0 pounds. a. By hand calculations (use only Excel, do not use StatTools), construct a 90% confidence interval for the mean shell strength. To determine the appropriate value of Z multiple, use either Excel function or the following Z values: z0.9 = 1.282, z0.95 = 1.645, z0.975 = 1.960, z0.99 = 2.326, z0.995 = 2.576 Present the confidence interval in the form point estimate ± margin of error. Show your work to receive full credit. b. Interpret the confidence interval within the context of the problem. c. What sample size is needed to have 90% confidence of estimating the population mean shell strength to within ± 0.5

Expert Solution