Question

Beatriz takes a simple random sample of 350350350 orders from the more than 500050005000 total orders to her store and finds that 12\, percent of the sampled orders were returned. Assuming that it is really 9\%9%9, percent of all orders to her store which were returned, what is the approximate probability that more than 12\, percent of the sampled orders would have been returned

Answer 1

Answer:

0.02493

Step-by-step explanation:

We are to Find :

P(p > 0.12) ;

This is equivalent to:

1 - P(p ≤ 0.12)

Using the relation :

1 - P((p - po) / (√(po(1 -po)) / n))

1 -P((Z ≤0.12 -0.09) / (√(0.09(1 -0.09)) / 350))

1 -P((Z≤0.03 / (√(0.09(0.91))/350))

1 - P((Z≤0.03 / 0.0152970))

1 - P((Z≤1.96116)

1 - 0.97507 (from Z probability calculator)

= 0.02493