The following problem refers to problem $30.$

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An appliance manufacturer wants to contract with a repair shop to handle authorized repairs in Indianapolis. The company has set an acceptable range of repair times of $100$ to $120$ minutes. Two firms have submitted bids for the work. In test trials, the A firm had a mean repair time of $90$ minutes with a standard deviation of $5$ minutes, and the B firm had a mean repair time of $85$ minutes with a standard deviation of $6$ minutes.

Which firm would you choose?$$

a$)$ Firm A

b$)$ Firm B

c$)$ Choose either A or B because they are both the same.

d$)$ None of them