Chapter 5.1, Problem 21E

(a)

To determine

To Explain: the reason of sample outcomes 55 out of 100 said “Yes” does not allow convincing proof that more than half of the school’ student recycle.

Answer to Problem 21E

Dot plot is having many points above the sample proportion of 0.55

Explanation of Solution

Given:

  

55 outcomes from 100 students said “Yes”

  $\frac{55}{100}=0.55$

By seeing the dot plot, it is notice that the proportion of 0.55 has many dots above it. Therefore it is too much likely to get a proportion of 0.55 if the true proportion is 0.5 and then there is not enough proof to help the claim that more than half of the school’s students recycle.

(b)

To determine

To Explain: the reason of result would offer convincing proof that a majority of the school’s students recycle if 60 students in the class’s sample had said “Yes”.

Answer to Problem 21E

There is only one dot plot above the 0.63 and no contained dots to the right of 0.63 in the plot.

Explanation of Solution

Given:

  

55 outcomes from 100 students said “Yes”

  $\frac{63}{100}=0.63$

By seeing the dot plot, it is observed that the proportion of 0.63 has only one dot above it and there is no contained the dot plot to the right of 0.63, therefore is too much likely to get a proportion of 0.63 if the true proportion is 0.5 and then there is enough proof to help the claim that more than half of the school’s students recycle.