Statisctics

  

Activity 1 – CLO 1, CLO 2, CLO 3, CLO 4

 
 

1. Ball bearing manufacturing is a highly precise business      in which minimal part variability is critical. Large variances in the size      of the ball bearings cause bearing failure and rapid wear-out. Production      standards call for a maximum variance of .0001 inches. Gerry Liddy has      gathered a sample of 15 bearings that shows a sample standard deviation of      .014 inches. Use ɑ = .10 

a. Please determine whether the sample indicates that the maximum acceptable variance is being exceeded. 

b. What is the p value?

2. The grade point averages of 352 students who completed a college course in financial accounting have a standard deviation of .940. The grade point averages of 73 students who dropped out of the same course have a standard deviation of .797. 

a. Do the data indicate a difference between the variances of grade point averages for students who completed a financial accounting course and students who dropped out? 

b. Use ɑ = .05 level of significance. 

c. What is the p value? 

Note: F of alpha / 2 with degrees of freedom 351 and 72 which yields 0.025 area under its graph to the right is 1.466