Am struggling to come to grips with what has been quoted in the examiners solution In broad terms if there is a less than one in twenty chance that the difference from average is just a random thing its generally worth more investigation With average complaints of 6 from mailings to 10000 custiers it works out that you can expect 10 or more complaints about once every 20 months!! Gone aways Average of 200 suggest you can expect 177 or fewer about one every 20 months.So if you had 160 this month that is is significant!! Am not sure how we quote these stats from the information provided in the question!! Help
Hi, Could one of the tutors please explain this solution? I just cannot see how I could have explained it and cannot understand any of the calculations. Thanks,