Question

It has been estimated that 21% of all university students switch majors within their first two years of starting classes. If a random sample of 400 third-year students is taken at a city university, what is an estimate of the probability that 17% or less had switched majors within their first two years? Use Appendix B.1 for the z-values. (Round the z-value to 2 decimal places and the final answer to 4 decimal places.) Probability

Answer 1

Solution :

Given that ,

p = 0.21

1 - p = 0.79

n = 400

= p = 0.21

= (p*(1-p))/n =  (0.21*0.79)/ 400 = 0.01832

P( 0.17) = P(( - ) / (0.17 - 0.21) / 0.01832)

= P(z < -2.18)

= 0.0146

Probability = 0.0146