Question

A researcher wants to estimate the percent of the population that uses the radio to stay informed on local news issues. The researcher wants to estimate the population proportion with a 99% level of confidence. He estimates from previous studies that no more than 50% of the population stay informed on local issues through the radio. The researcher wants the estimate to have an error of no more than 0.05. The necessary sample size is at least _______. Group of answer choices 333 666 999 555 888

Answer 1

Solution :

Given that,

= 0.5

1 - = 1 - 0.5 = 0.5

margin of error = E = 0.05

At 99% confidence level the z is,

= 1 - 99%

= 1 - 0.99 = 0.01

/2 = 0.005

Z/2 = 2.58 ( Using z table )

Sample size = n = (Z/2 / E)2 * * (1 - )

= (2.58 / 0.05)2 * 0.5 * 0.5

=666

Sample size =666