Question

Use the data in the following table, which lists drive-thru order accuracy at popular fast food chains. Assume that orders are randomly selected from those included in the table. If two orders are selected, find the probability that they are both accurate. Complete parts (a) and (b) below.

a. Assume that the selections are made with replacement. Are the events independent?

The probability is __. The events __ (are, are not) independent.
(Do not round until the final answer. Round to four decimal places as needed.)

Answer 1

a. If the selection is made with replacement, they are NOT independent because they affect each other.

b. The probability of selecting TWO accurate orders is .7157 and the events ARE independent.

Explanation:

Add the accurate orders:

315+273+248+125=961

Add the inaccurate orders:

38+56+37+17=148

148/961=0.1540 probability of getting ONE inaccurate order

1.0-0.1540=0.846 probability of selecting ONE accurate order

0.846 * 0.846 = 0.7157 the probability of selecting TWO accurate orders

Therefore, the probability is .7157 and the events ARE independent.