Question

15. A local newspaper polls 400 voters in an attempt to predict whether the budget will pass. Suppose that the budget actually has the support of 52% of the voters. What is the probability that the newspaper’s sample will lead them to predict defeat (less than 50% support the budget)?

a. 0.212 b. 0.52 c. -0.801 d. 0.025

Answer 1

Solution

=  [p ( 1 - p ) / n] =   [(0.52 * 0.48) / 400 ] = 0.025

P( < 0.50) =

= P[( - ) / < (0.50 - 0.52) / 0.025]

= P(z < -0.8)

= 0.212

a)