Question

It has been estimated that 17% of all university students switch majors within their first two years of starting classes. If a random sample of 430 third-year students is taken at a city university, what is an estimate of the probability that 15% 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

=  [p ( 1 - p ) / n] =   [(0.17 * 0.83) / 430 ] = 0.018115

P( < 0.15) =

= P[( - ) / < (0.15 - 0.17) / 0.018115]

= P(z < -1.10)

= 0.1357

Probability = 0.1357