Question

The proportion of eligible voters in the next election who will vote for the incumbent is assumed to be 52.7%. What is the probability that in a random sample of 470 voters, less than 235 say they will vote for the incumbent? Remember to use the continuity correction and calculate z-scores to at least 3 decimal places. Give probabilities to 4 decimal places.

Probability =

Answer 1

Result:

The proportion of eligible voters in the next election who will vote for the incumbent is assumed to be 52.7%. What is the probability that in a random sample of 470 voters, less than 235 say they will vote for the incumbent? Remember to use the continuity correction and calculate z-scores to at least 3 decimal places. Give probabilities to 4 decimal places.

Probability =0.1114

n=470, p=0.527

Expectation = np = 247.69

Variance = np(1 - p) = 117.15737

Standard deviation = 10.8239

Z value for 235 with continuity correction, z =(234.5-247.69)/10.8239

=-1.219

P( x <235) = P( z < -1.219)

=0.1114