A company manager plans to purchase a machine. The company requires a high quality machine. The manager is currently considering two companies that supply this machine. The machine from company A can...

A company manager plans to purchase a machine. The company requires a high quality machine. The manager is currently considering two companies that supply this machine. The machine from company A can produce approximately
a
 units in average per day, but the standard deviation of this machine is about
c
 units per day; while the machine from company B can produce approximately
b
 units in average per day, but the standard deviation of this machine is about
d
 units per day. Note:
a
 >
b
 and
c
 >
d
. Both of these two companies guarantee at least 10 years life. In addition, both prices are similar although machine A is a little bit higher. Price is not the main concern for the manager because both prices are under their budget. However, the manager cannot decide which machine should be purchased, because he is not sure which test he needs to conduct. Can you recommend the manager which test the manager should conduct? Should the manager conduct the test about the difference between two population means or the test about the difference between two population variances or both? Discuss and explain your reasons. You must provide your statistical analysis and reasons.