Answer:
The standard deviation of the sample mean is
Step-by-step explanation:
From the question we are told that
The mean is
The standard deviation is
The sample size is
Generally the standard deviation of the sample mean is mathematically represented as
substituting values
Answer:
22.60% probability that exactly 3 people are repeat offenders
Step-by-step explanation:
For each driver arrested selected, there are only two possible outcomes. Either they are repeat offenders, or they are not. The probability of an arrested driver being a repeat offender is independent from other arrested drivers. So we use the binomial probability distribution to solve this problem.
Binomial probability distribution
The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.
In which is the number of different combinations of x objects from a set of n elements, given by the following formula.
And p is the probability of X happening.
In Illinois, 9% of all drivers arrested for DUI (Driving Under the Influence) are repeat offenders;
This means that
Suppose 28 people arrested for DUI in Illinois are selected at random.
This means that
a) What is the probability that exactly 3 people are repeat offenders
This is
22.60% probability that exactly 3 people are repeat offenders