Stats in class set for class 13 Name (8) 1. Let X = the number of incorrect answers on an exam and the probability distribution for X is given as: X P (x) 0 .5 1 .1 2 .4 a) Find the mean and standard deviation for x Mean = standard deviation = b) Interpret the mean found in part a) (10) 2. We know that 63% of Americans voted in the last election a) Find the probability from a sample of 35 Americans more than 20 voted in the last election? Answer: b) Find the probability from a sample of 20 Americans less than 5 voted in the last election? Answer: c) Find the probability from a sample of 400 Americans more than 100 did not vote in the last election? Answer: d) If I sample 45 Americans on average how many voted in the last election and what was the standard deviation mean = standard deviation =