Question

Twenty percent of all adult males did not visit their physicians’ offices last year. The probability that more than 18% of adult males in a sample of 800 did not visit their physicians’ offices last year is approximately:

Group of answer choices

0.9236

0.4236

0.1378

0.0764

Answer 1

Solution

Given that,

p = 0.20

1 - p = 1-0.20=0.80

n = 800

= p =0.20

=  [p( 1 - p ) / n] = [(0.20*0.80) / 800 ] = 0.01414

P( >0.18 ) = 1 - P( <0.18 )

= 1 - P(( - ) / < (0.18-0.20) / 0.01414)

= 1 - P(z <-1.4286 )

Using z table

= 1 -0.0764

=0.9236

probability=0.9236