Question

The proportion of married people in a city is 0.4 if a sample of 49 people is taken from that city. Calculate the probability that the sample proportion is greater than 0.5.

Answer 1

Solution

Given that,

p = 0.4

1 - p = 1-0.4=0.6

n = 49

= p =0.4

=  [p( 1 - p ) / n] = [(0.4*0.6) / 49 ] = 0.07

P( >0.5 ) = 1 - P( <0.5 )

= 1 - P(( - ) / < (0.5-0.4) / 0.07)

= 1 - P(z < 1.43)

Using z table

= 1 - 0.9236

probability=0.0764