You want to obtain a sample to estimate a population proportion. At this point in time, you have no reasonable preliminary estimation for the population proportion. You would like to be 98% confident that you estimate is within 2.5% of the true population proportion. How large of a sample size is required?

Can someone me with #s 8, 9, and 11. with just one of the three also works. prove using only trig identities.

Joey is asked to name a quadrilateral that is also a rhombus and has 2 pairs of parallel sides. should be his answer

1. according to the internal revenue service, the mean tax refund for the year 2007 was $2,708. assume the standard deviation is $650 and that the amounts refunded follow a normal probability distribution. a. what percent of the refunds are more than $3,000? b. what percent of the refunds are more than $3,000 but less than $4,000? c. what percent of the refunds are less than $2,000?