SOLUTION: a firm claims that only 10% of its accounts receivables are over 30 days past due. The bank that supplies working capital or interim loans to the firm is suspect of the figure and

Algebra ->  Probability-and-statistics -> SOLUTION: a firm claims that only 10% of its accounts receivables are over 30 days past due. The bank that supplies working capital or interim loans to the firm is suspect of the figure and       Log On


   



Question 936153: a firm claims that only 10% of its accounts receivables are over 30 days past due. The bank that supplies working capital or interim loans to the firm is suspect of the figure and accordingly takes a random sample of 100 accounts of the firm. find the probability that the sample proportion, p, will be ?
a) between 9% and 10%
b) at least 12%

Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
P(x <.09) = P(z < -.01/sqrt(.10*.90/100))
P(.09 < x < .10) = .5 - P(z < .09) = .5 - normalcdf(-100, -1/3)
.....
P( x <.12) = P(z< .02/sqrt(.10*.90/100)) = normalcdf(-100, 2/3)