Practice!

Sample Problem

Use your graphing calculator to construct a histogram showing the probability distribution for X, where X is a random variable that represents the sum when you took two balls from the balls above randomly. Based on this histogram, what is the probability of getting a 4, 7, or 11? Enter your number as an improper, irreducible, fraction in the form “a/b”.

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Solution

The histogram shows that 4 has a probability of  7 has a probability of , and 11 has a probability of . Thus, the probability of getting one of these sums is .