According to the Nielsen Company, the mean number of TV sets in a U.S. household in 2013 was 2.24. Assume the standard deviation is 1.3. A sample of 95 households is drawn.
What is the probability that the sample mean number of TV sets is less than 2.4?
a) 0.7486
b) 0.2514
c) 0.8315
d) 0.1685