The standard deviation of the breaking strengths of certain cables produced by a company is given as 240 pounds. After a change was introduced in the process of manufacture of these cables, the breaking strengths of a sample of 8 cables showed a standard deviation of 300 pounds. Investigate the significance of the apparent increase in variability, using a significance level of (a) 0.05 (b) 0.01.© BrainMass Inc. brainmass.com March 4, 2021, 6:07 pm ad1c9bdddf
This problem is a test of hypothesis comparing the variance ( and standard deviation) of a new distribution with a known variance from another distribution. A step-by-step process is used, all formulas and calculations are shown and each step is explained.