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.
drive - thru restaurant

	a	b	c	d
order not accurate	39	56	31	11

if one order is selected, find the probability of getting an order from restaurant a or an order that is accurate. are the events of selecting an order from restaurant a and selecting an accurate order disjoint events?
the probability of getting an order from restaurant a or an order that is accurate is
(round to three decimal places as needed.)

Explanation:

Step1: Calculate total number of orders

$318 + 266+243 + 150+39 + 56+31 + 11=1114$

Step2: Calculate number of orders from Restaurant A

$318 + 39=357$

Step3: Calculate number of accurate orders

$318+266 + 243+150 = 977$

Step4: Calculate number of accurate orders from Restaurant A

$318$

Step5: Use the addition - rule for probability

$P(A\ or\ accurate)=P(A)+P(accurate)-P(A\ and\ accurate)$
$P(A)=\frac{357}{1114}$, $P(accurate)=\frac{977}{1114}$, $P(A\ and\ accurate)=\frac{318}{1114}$
$P(A\ or\ accurate)=\frac{357 + 977-318}{1114}=\frac{1016}{1114}\approx0.912$

Step6: Determine if events are disjoint

Disjoint events cannot occur at the same time. Since there are accurate orders from Restaurant A, the events of selecting an order from Restaurant A and selecting an accurate order are not disjoint.

Answer:

The probability is approximately $0.912$. The events are not disjoint.