In: Statistics and Probability
Sampling voters. Your state representative is
planning on supporting a bill legalizing same-sex marriage in your...
Sampling voters. Your state representative is
planning on supporting a bill legalizing same-sex marriage in your
state and wants to estimate the proportion of voters in her
district who support this bill. She mails a survey to an SRS of
1300 registered voters in her district, and 800 surveys are
returned. In the sample of 800 surveys returned to your state
representative, 506 are from female voters.
a) In her district, voter registration records
show that 54% of registered voters are female. If the 800 returned
surveys are an SRS of registered voters, do you feel that the
difference between the proportion of female voters that responded
to the survey and the population proportion of 54% can be easily
explained by chance variation?
Select the correct hypotheses:
The sample proportion of females is (round your answer to two
decimal places): pˆ=p^=
The test statistic is (round your answer to two decimal
places):
The P-value is approximately:
You conclude:
|
There is overwhelming evidence that the sample is a good
representation of the population of the district in terms of
sex. |
|
|
There is overwhelming evidence that the sample does not
represent the population of the district in terms of sex. |
|
b) Among the 800 surveys that are returned, 72%
support the bill. If women are more likely to support the bill
legalizing same-sex marriage than men, what would be the likely
direction of the bias in the estimate of the proportion of
registered voters who support the bill?
|
The direction of the bias would be to decrease the proportion
in the survey responses of those who favor it. |
|
|
The direction of the bias would be to increase the proportion
in the survey responses of those who favor it. |
|