High School

In an election year, 42% of the voters support the incumbent. You conduct a straw poll and randomly select 8 voters. Determine the probability that exactly 5 of them will support the incumbent.

Answer :

The binomial probability problem, requiring the use of the binomial probability formula to calculate the chance of exactly 5 out of 8 voters supporting the incumbent given a 42% support rate.

The probability of a specific outcome in a binomial experiment. Here, we need to use the binomial probability formula: P(X = k) = C(n, k) * p^k * (1-p)^(n-k), where:

  • C(n, k) is the combination of n items taken k at a time
  • p is the probability of success on any given trial (42% or 0.42 in this case)
  • k is the number of successes (5 voters supporting the incumbent)
  • n is the total number of trials (8 voters selected)

By applying the formula, we can calculate the probability that exactly 5 out of 8 randomly selected voters will support the incumbent when the support is at 42% overall.