Below is a probability distribution for the number of days worked per week for a sample of adults:

Question

Below is a probability distribution for the number of days worked per week for a sample of adults:

Task 1: Find the mean of the probability distribution. (remember not to use the built in excel functions!)

Task 2: Find the standard deviation of the probability distribution (remember not to use the built in excel functions!)

Task 3: What is the probability that an adult from the sample works at least 4 days a week?

Answer 1

Mean = sum (x * P(x))

variance = sum(x^2 * P(x)) - mean^2

standard deviation = square root of variance

P(x > = 4) = sum of P(x) for x = 4, 5, 6, 7