SOLUTION: 10. In a poll, 341 out of 775 New York voters surveyed indicated that they approve of the job DeBlasio has done as mayor. Make a 99% confidence interval for the percentage of all

Question 971551: 10. In a poll, 341 out of 775 New York voters surveyed indicated that they approve of the job DeBlasio has done as mayor. Make a 99% confidence interval for the percentage of all New York voters who would approve of DeBlasio�s performance as mayor. Describe the meaning of the interval that you found.

Answer by Boreal(15235) (Show Source): You can put this solution on YOUR website!
ph=341/775 = 0.44
SE= sqrt [p(1-p)/n]= 0.01783
z.99 ci= 2.576
z * SE (+/-)= .046
A 99% CI = [0.394, 0.486]
We do not know the true proportion of voters who approve. We are very highly confident that the true value is contained in the interval above.
If we were to perform 100 such tests, 99 of them would contain the parameter. We wouldn't know which 99. We are 99% confident that a majority of voters do not approve of the job. We don't say probable, we say confident.
It's called confidence, because the true value is either in or out of the interval, and that is a dichotomous issue where probability would be 0 or 1.
RELATED QUESTIONS
10. In a poll, 341 out of 775 New York voters surveyed indicated that they approve of the (answered by stanbon)

Political polls typically sample randomly from the U.S population to investigate the... (answered by rothauserc)

A poll shows that 70% of all voters approve of the mayor's work. On three separate... (answered by MathLover1)

An election poll reported that a candidate has an approval rating of 44% with a margin of (answered by ewatrrr)

A poll of 200 registered voters was taken before the election for mayor of Springdale.... (answered by richwmiller)

Here is the problem and I honestly am not sure what to do. Is Sample size all voters in... (answered by stanbon,Edwin McCravy)

A New York Times article about poll results states, "In theory, in 19 cases out of 20,... (answered by stanbon)

48% of New York city residents are New York state natives. a. If 3 people are surveyed... (answered by ikleyn)

The city of Raleigh has 10400 registered voters. There are two candidates for city... (answered by ikleyn)