Question

write the null and alternative hypotheses fore each situation described below and indicate whether each test would be left-tailed, right-tailed, or two tailed.

1. a cereal manufacturer claims that, for a particular brand of cereal, the average amount of cereal in a box is 15 ounces. A consumer advocate believes that the boxes are undefiled.

2. in the past, it was reported that 35% of American adults were obese. A health researcher believes that the proportion is now higher than that.

3. a homeowner claims that the average monthly water bill is $65.99. A potential buyer believes that the average bill differs from that.

Answer 1

(A) claim is that, for a particular brand of cereal, the average amount of cereal in a box is 15 ounces and advocate believes that the boxes are undefiled, i.e. not equal to mean amount

so it is a two tailed hypothesis

(B) it was reported that 35% of American adults were obese. A health researcher believes that the proportion is now higher than that.

it is clear that the health researcher believes that the proportion is now higher than that, so it is a right tailed hypothesis for proportion testing using z test

(C) claims that the average monthly water bill is $65.99 and  potential buyer believes that the average bill differs from that. Differs means either lower or higher than the average bill

So, it is a two tailed hypothesis