Imagine a set of 100 customers and each one of them is asked which one of the six promotional techniques influenced their decision to buy the item. Note here that each customer has to choose only one of those six techniques. Out of the 90 customers that selected one of the four choices, 22 indicated coupons and 18 indicated store displays. When they ask what fraction indicated coupons or store displays, they are asking for that set of customers who chose either coupons or store displays as the promotional technique that influenced their decision. The “or” in this sense is additive.
The statement “what fraction indicated coupons and store displays” would not make sense here because a customer cannot choose both coupons and store displays to influence their decision. It has to be one or the other. I hope this makes sense.
Could you please help explain why the stem says “or” “what fraction indicated either coupons or store displays” then we have a sum (22+18)?
I think it should be 22/90 or 18/90.
(22+18)/90 stem should be “what fraction indicated coupons and store displays”
Am I missing anything?
Imagine a set of 100 customers and each one of them is asked which one of the six promotional techniques influenced their decision to buy the item. Note here that each customer has to choose only one of those six techniques. Out of the 90 customers that selected one of the four choices, 22 indicated coupons and 18 indicated store displays. When they ask what fraction indicated coupons or store displays, they are asking for that set of customers who chose either coupons or store displays as the promotional technique that influenced their decision. The “or” in this sense is additive.
The statement “what fraction indicated coupons and store displays” would not make sense here because a customer cannot choose both coupons and store displays to influence their decision. It has to be one or the other. I hope this makes sense.
Thanks a lot!