# Statistical and probabilty questions part 1

• Sep 27th 2009, 12:58 PM
mayguy
Statistical and probabilty questions part 1
Suppose that the time between ordering and receiving your order in quick takeaway fast food chains has been found to be normally distributed with a mean time f 10 minutes and a standard deviation of 2.5 minutes.

Q1. What is the probability that a randomly selected person will have to wait at least 6 minutes before his or her order is served

Q2. In an advertising campaign raylene brown the manager of quick take-away, offers a coupon for a free bottle of wine with the next purchase for al customers whose service time exceeds 10 minutes.

Q3. What proportion of customers would receive coupons if the process were improved so that the mean service time was reduced to 5.5 minutes and the stand deviation remained at 2.5 minutes?

Q4. Once the mean service time was reduced to 5.5 minutes, would RAylene be better off focusing on improvement that reduced the mean 4.5 minutes or improvement that reduced the standard deviation to 1.5 minutes. Explain the reasons for your answers.

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