Question

Just before a referendum on a school​ budget, a local newspaper polls 407 voters to predict whether the budget will pass. Suppose the budget has the support of 52​% of the voters. What is the probability that the​ newspaper's sample will lead it to predict​ defeat?

Answer 1

Solution

Given that,

p = 52% = 0.52

1 - p = 1 - 0.52 = 0.48

n = 407

= p = 0.52

=  p ( 1 - p ) / n

=   (0.52 * 0.48) / 507 = 0.0222

P( < 0.5) =

= P(( - ) / < (0.5 - 0.52) / 0.0222)

= P(z < -0.90 )

= 0.1841

Probability = 0.1841