Question

Pinky Bauer, Chief Financial Officer of Harrison Haulers, Inc., suspects irregularities in the payroll system. If 10% of the 5,000 payroll vouchers issued since January 1, 2000, have irregularities, the probability that Pinky's random sample of 200 vouchers will have a sample proportion of between .06 and .14 is ___________.

Answer 1

P(p < A) = P(Z < (A - )/)

Here, = 0.10

n = 200

= = 0.10

=

=

= 0.0212

P(sample proportion of between 0.06 and 0.14) = P(p < 0.14) - P(p < 0.06)

= P(Z < (0.14 - 0.10)/0.0212) - P(Z < (0.06 - 0.10)/0.0212)

= P(Z < 1.89) - P(Z < -1.89)

= 0.9706 - 0.0294

= 0.9412