In: Statistics and Probability
1. In a recent report released by Consumer Reports, it was reported that 7 in 10 auto accidents involve a single vehicle (thus, 3 out of 10 involve multiple vehicles). Suppose 15 accidents are randomly selected. Let x = the number of accidents involving a single vehicle.
a. What is the probability that less than 14 accidents involve a single vehicle?
b. What is the mean number of single vehicle accidents? What is the standard deviation?
c. What is the probability at least 2 accidents are multiple vehicle accidents?
Answer a)
We have to find P(X < 14) = 1 - P(X ≥ 14)
P(X ≥ 14) = 0.0353
P(X < 14) = 1 - 0.0353
P(X < 14) = 0.9647
The probability that less than 14 accidents involve a single vehicle is 0.9647
Answer b)
The population proportion of success is p = 0.7
Answer c)
We have to find P(X ≥ 2) = 1 - P(X ≤ 1)
P(X ≤ 1) = 0.0353
P(X ≥ 2) = 1 - 0.0353
P(X ≥ 2) = 0.9647
The probability at least 2 accidents are multiple vehicle accidents is 0.9647