Use the following information for the next five exercises. Two types of wireless operating systems are tested to determine the difference in system failure rates. Out of $150$ phones at random, $15$ had a system with OS$1.$ Out of $150$ phones with OS$2,9$ crashes occurred within the first seven hours of OS$2$ launch.

A$.$ Is this a test of capacity or quantity?

b$.$ What is a random variable?

c$.$ Specify blank and optional errors.

d$.$ What is p$-$value?

e$.$ About the two operating systems, what do they do$?$