2 The standard deviation of the distribution of the sample p

2. The standard deviation of the distribution of the sample proportion in the previous problem is about ______.

Solution

Answer:

Suppose that 35% of all adults in a population would say “good” and 65% would say “bad” if they were asked how they view the state of the economy. An opinion poll asks this question of an SRS of 1000 adults from the population. In repeated samples, the sample proportion who say “good” would follow a normal distribution, with the mean having a value of   0.35

(Give your answer to 2 decimal places.)

2. The standard deviation of the distribution of the sample proportion in the previous problem is about ______.

standard deviation = sqrt(p*q/n)

=sqrt(0.35*0.65/1000)

=0.01508

=0.02 ( two decimals)

3. A survey of folk music fans yields this 95% confidence interval estimate of the proportion of fans who love the music of David Wilcox: 0.74 to 0.86. To the nearer percentage point, the margin of error for this survey is ______.

(Give your answer to 2 decimal places.)
margin of error = (0.86-0.74)/2

=0.06

4. The American Community Survey (ACS) will replace the census long form starting with the 2010 census. The main part of the ACS contacts households at 250,000 addresses by mail each month, with follow-up by phone and in person if there is no response. Each household answers questions about its housing, economic, and social status.

What is the population for the ACS?

All households in the country or American Community.