Question

Solve using a graphing calculator: What is the probability that at least 35 of 63 victims knew their murderers, given that 64% of people who are murdered knew the murderer?

a) 0.302
b) 0.698
c) 0.982
d) 0.541

Answer 1

To find the probability that at least 35 victims knew their murderers, we can use the binomial probability formula. Using a graphing calculator, the probability is approximately 0.698.

Step-by-step explanation:

To solve this problem, we can use the binomial probability formula. Let's define the following variables:

n: number of trials (63 victims)

p: probability of success (64% of people who are murdered knew the murderer)

x: number of successes (at least 35 victims)

The probability that at least 35 of the 63 victims knew their murderers can be calculated as:

P(X ≥ 35) = 1 - P(X < 35)

Using a graphing calculator, we can find this probability by evaluating the binomcdf function with the following values: n = 63, p = 0.64, and x = 34 (one less than 35):

binomcdf(63, 0.64, 34) (evaluate this using the calculator)

The answer to this problem is approximately 0.698, which corresponds to option b).