Question

Problem Seven The table lists drive-thru order accuracy at popular fast food chains (data from a 2016 QSR Drive-Thru Study). Assume that orders are randomly selected from those included in the table.

If one order is selected, what is the probability of the order:

McDonald's 334 Burger King 288 Wendy's 243 Taco Bell 145 Order Accurate Order Not Accurate 28 30 37 13

A. Being Accurate?

B. NOT being from Wendy’s?  

C. Being from McDonald’s OR NOT Accurate?

D. Are the events of selecting an order from McDonald’s and selecting an accurate order mutually exclusive events? Explain your reasoning.

Answer 1

	McD	Burger King	Wendy's	Taco bell	Total
Accurate	334	288	243	145	1010
not accurate	28	30	37	13	108
Total	362	318	280	158	1118

A)

P( Being Accurate ) =1010/1118 =0.9034

B)

P( NOT being from Wendy’s )=1-P(from Wendy’s ) =1-280/1118 = 0.7496

C)

P( Being from McDonald’s OR NOT Accurate ) =P(McD)+P(not Accurate)-P(MCD and Not Accurate)

=(362/1118)+(108/1118)-(28/1118)

=0.3953

D)

No since both events contains 334 element in common