Information Xylitol is a food sweetener that may also have antibacterial propert
ID: 3300417 • Letter: I
Question
Information
Xylitol is a food sweetener that may also have antibacterial properties. In an experiment conducted in Finland, researchers investigated whether the regular use of chewing gum containing xylitol could reduce the risk of a middle ear infection for children in daycare centers (Uhari et al., 1998). The investigators randomly divided 533 children in daycare centers into three groups. One group regularly chewed gum that contained xylitol, another group regularly took xylitol lozenges, and the third group regularly chewed gum that did not contain xylitol (placebo gum). The experiment lasted for 3 months and for each child the researchers recorded whether the child had an ear infection during that period. A table containing the study results is below. Use this table to answer the following two questions.
Information
Ear Infections and the Use of Xylitol.
Question 11 (1 point)
What is the probability that a randomly selected child from this study developed an ear infection?
Question 11 options:
a) 39/176 = 0.222
b) 49/117 =0.419
c) 117/533 = 0.220
d) 176/533 = 0.330
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Question 12 (1 point)
What is the probability that a randomly selected child who took the Placebo gum developed an ear infection?
Question 12 options:
a) 49/178 = 0.275
b) 49/533 = 0.092
c) 49/117 = 0.419
d) 117/533 = 0.220
a) 39/176 = 0.222
b) 49/117 =0.419
c) 117/533 = 0.220
d) 176/533 = 0.330
Explanation / Answer
What is the probability that a randomly selected child from this study developed an ear infection?
Ans : c) 117/533 = 0.220
What is the probability that a randomly selected child who took the Placebo gum developed an ear infection?
Ans : a) 49/178 = 0.275