Question

Find the probability that less than 40% of a random sample of 200 people will be blood type O+ if the population proportion is 39%

Enter only the probability.

Answer 1

Solution

Given that,

p = 0.39

1 - p = 1 - 0.39 = 0.61

n = 200

= p = 0.39

=  [p ( 1 - p ) / n] =   [(0.39 * 0.61) / 200] = 0.0345

P( < 0.40)

= P[( - ) / < (0.40 - 0.39) / 0.0345 ]

= P(z < 0.29)

Using z table,

= 0.6141