Answer:
To find the mean for the binomial random variable x=20:
Mean = N * p
where N is the number of trials (20) and p is the probability of success on a single trial.
The standard deviation for the binomial random variable x=4:
Standard deviation = sqrt((Np(1-p)))
where N is the number of trials (4) and p is the probability of success on a single trial.
To find P(18< x <24):
Probability = [P(x<24) - P(x<18)]
Step-by-step explanation: