Use @RISK to draw a binomial distribution that results from 50 trials with probability of success 0.3 on each trial, and use it to answer the following questions.
a. What are the mean and standard deviation of this distribution?
b. You have to be more careful in interpreting @RISK probabilities with a discrete distribution such as this binomial. For example, if you move the left slider to 11, you should find a probability of 0.139 to the left of it. But is this the probability of “less than 11” or “less than or equal to 11”? One way to check is to use Excel’s BINOMDIST function. The formula =BINOMDIST(k,n,p,1) calculates the probability that a binomial random number with parameters n and p is less than or equal to k. (The last argument, 1, ensures that you get a cumulative probability.) Use this function to interpret the 0.139 value from @RISK.
c. Using part b to guide you, use @RISK to find the probability that a random number from this distribution is greater than 17. Check your answer by using the BINOMDIST function appropriately in Excel.
Already registered? Login
Not Account? Sign up
Enter your email address to reset your password
Back to Login? Click here