In: Statistics and Probability
A researcher believes that 8% of males smoke cigarettes. If the researcher is correct, what is the probability that the proportion of smokers in a sample of 512 males would differ from the population proportion by greater than 3%? Round your answer to four decimal places.
n = 512
= 8% =0.08
1 - = 1 - 0.08 = 0.92
= = 0.08
= √ ( 1 - ) / n
= √ 0.08 * 0.92 / 512
= 0.0120
= 0.0120
P( > 0.03 )
1 - P ( 0.05 < < 0.11 )
1 -P ( 0.05 - 0.08 / 0.0120 ) < ( - / ) < ( 0.11 - 0.08 / 0.0120)
1 -P ( - 0.03 / 0.0120 < z < 0.03 / 0.0120 )
1 - P (-2.5 < z < 2.5 )
1 - P ( z < 2.5) - p ( z < -2.5)
Using z table
= 1 - ( 0.9938 - 0.0062)
= 1 - 0.9876
= 0.0124
Probability = 0.0124.