Statistics

In a survey of 1037 adults, ages 65 and over, 643 were concerned about getting the flu.

a) Find the point estimate for the population proportion , p , of those concerned about getting the flu.

b) Construct a 90% Confidence Interval for the population proportion.

c) How big a sample size would be needed to allow for a 2% margin of error?

1. 👍
2. 👎
3. 👁
1. Use a proportional confidence interval formula.

CI90 = p + or - (z-value)(√ pq/n)
Find z-value using a z-table representing 90%. p = 643/1037 (convert to a decimal). q = 1 - p. n = 1037 (sample size). Plug values into the formula and calculate the interval.

Formula to find sample size:
n = [(z-value)^2 * p * q]/E^2
... where n = sample size, z-value is the same as above, p and q are the same as above, ^2 means squared, * means to multiply, and E = .02 (for 2%).
Plug values into the formula and calculate n.

I hope this will help get you started.

1. 👍
2. 👎

Similar Questions

1. Math

a citizens group wants to determine people's opinions about a new road. The members of the group conduct a survey at the largest part of the mall in the city. Which best describes the sampling method used by the citizens' group?

2. Statistics

One of the questions in the Pew Internet & American Life Project asked adults if they used the Internet, at least occasionally. The results showed that 454 out of 478 adults aged 18 - 29 answered yes; 741 out of 833 adults aged 30

3. Statistics

A recent survey found that 63% of all adults over 50 wear glasses for driving. In a random sample of 80 adults over 50, what is the mean and standard deviation of those that wear glasses?

4. Statistics

A recent survey found that 70% of all adults over 50 wear glasses for driving. You randomly select 30 adults over 50, and ask if he or she wears glasses. Decide whether you can use the normal distribution to approximate the

1. Statistics

A recent survey found that 70% of all adults over 50 wear glasses for driving. You randomly select 30 adults over 50, and ask if he or she wears glasses. Decide whether you can use the normal distribution to approximate the

2. Mathematics

Jon is working on a city councilperson’s election campaign. He wants to survey potential voters about their opinions. Which is the best way for him to gather a sample? Attend a speech given by the councilman and survey audience

3. Statistics

One of the questions on a survey of 1,000 adults asked if today's children will be better off than their parents (Rasmussen Reports website, October 26, 2012). Representative data are shown in the DATAfile named ChildOutlook. A

4. Statistics

A recent survey found that 72% of all adults over 50 wear glasses for driving. In a random sample of 100 adults over 50, what is the mean and standard deviation of the numbe who wear glasses?

1. Stats - Help!!!

Determine which of the four levels of measurement is most appropriate for the statement below. Ages of survey respondents. A. Ratio B. Interval C. Ordinal D. Nominal an: B

2. History

What is the main reason other members of the EU are concerned about the British decision to leave the EU? A. They are concerned that other nations will want to leave the EU after Britain. B. They are concerned that English will

3. Math (Statistics: Test Statistic, Proportion)

The Pew Research Center Internet Project, conducted on the 25th anniversary of the Internet, involved a survey of 857 Internet users (Pew Research Center website, April 1, 2014). It provided a variety of statistics on Internet

4. Statistics

Data in 1980 showed that about 48% of the adult population had never smoked cigarettes. In 2004, a national health survey interviewed a random sample of 5000 adults and found that 54% had never been smokers. Create a 95%