Please help solving question2. If it is possibleplease give me a detailed explanation! Thank you so much!

Question 2 An appliance manufacturer in Australia wants to contract with a repair shop to handle authorized repairs in Bangkok. The company has set an acceptable range of repair time from 50 minutes to 90 minutes. Two firms have submitted bids for the work. In test trials, Firm A had a mean repair time of 76 minutes with a standard deviation of 4.0 minutes. Firm B had a mean repair time of 72 minutes with a standard deviation of 6.0 minutes. Which firm would you choose? Explain your