what proportion of all americans believe the president is doing a good job? A recent poll found that 39% of 1000 randomly selected americans approved of the way George W. Bush is handling his job as president.
a)Does this mean that only 39% of americans approve of the way GWB is handling his job as president?
b) for a sample proportion, as long as the population is greater than 10 times the sample size, we can approximate the standard deviation to be sqrt(p)(1-p)/n. what is the standard deviation for this sample?
c)what is the critical value for a 90% confidence interval?

Question

what proportion of all americans believe the president is doing a good job? A recent poll found that 39% of 1000 randomly selected americans approved of the way George W. Bush is handling his job as president.
a)Does this mean that only 39% of americans approve of the way GWB is handling his job as president?
b) for a sample proportion, as long as the population is greater than 10 times the sample size, we can approximate the standard deviation to be sqrt(p)(1-p)/n. what is the standard deviation for this sample?
c)what is the critical value for a 90%  confidence interval?