Question

4. Use the data in the following table, which lists drive-thru order accuracy at popular fast food chains (data from a QSR Drive-thru Study). Assume that orders are randomly selected from those included in the table. I 3 points each] McDonald's Burger King Wendy 's Order Accurate329 Order Not Accu 33 264 54 249 31 Taco Bell 145 13 a. If one order is selected, find the probability of getting food that is not from McDonald's. b. If one order is selected, find the probability of getting an order that is not accurate. c. If one order is selected, find the probability of getting an order from McDonald's or an order that is accurate. Are the events of selecting an order from McDonald's and selecting an accurate order disjoint events? d. If one order is selected, find the probability of getting an order that is not accurate or is from Wendy's. Are the events of selecting an order that is not accurate and selecting an order from Wendy's disjoint events? e. If two orders are selected, find the probability that they are both from Taco Bell. f. If two orders are selected, find the probability that both of them are not accurate. g. If two orders are selected with replacement, find the probability that they are both accurate

Answer 1

	McD	Burger King	Wendy	Taco Bell	total
accurate	329	264	249	145	987
not accu	33	54	31	13	131
total	362	318	280	158	1118

a)

Probability=1-P(from Mcdonald)=1-362/1118 = 756/1118

b)

Probability =131/1118

c)

probability=(362+987-329)/1118 =1020/1118

No they are nt disjoint as they contain 329 sample elements in common

d)probability=(280+131-31)/1118 =380/1118

No they are nt disjoint as they contain 31 sample elements in common

e)

Probability=(158/1118)*(157/1117)=0.0199

f)

Probability=(131/1118)*(130/1117)=0.0136

g)Probability=(987/1118)*(987/1118)=0.7794