Deck 12: From Randomness to Probability

Question 1

A survey of families revealed that 58% of all families eat turkey at holiday meals, 44% eat
ham, and 16% have both turkey and ham to eat at holiday meals.
a.What is the probability that a family selected at random had neither turkey nor ham at
their holiday meal?
b.What is the probability that a family selected at random had only ham without having
turkey at their holiday meal?
c.What is the probability that a randomly selected family having turkey had ham at their
holiday meal?
d.Are having turkey and having ham disjoint events? Explain.

Answer 1

d.No, the events are not disjoint, since some families (16%) have both ham and turkey at
their holiday meals.

Question 2

Many school administrators watch enrollment numbers for answers to questions parents ask.
Some parents wondered if preferring a particular science course is related to the student's
preference in foreign language.Students were surveyed to establish their preference in
science and foreign language courses.Does it appear that preferences in science and foreign
language are independent? Explain.

Answer 2

Overall, 102 of 136, or 75%, preferred Spanish.35 of 51, or 68.6%, of students in Chemistry
had Spanish.23 of 33, or 69.6%, of students in Physics had Spanish, and 44 of 52, or 84.6%
of students in Biology had Spanish.Chemistry and Physics students were somewhat less
likely to take Spanish than Biology students.It appears that there is an association between
preference in science and foreign language.