In a pizza takeout restaurant, the following probability distribution was obtained for the number of toppings ordered on a large pizza. Find the mean and standard deviation for the random variable.
X 0. 1. 2. 3. 4
P (x) 0.1 0.3 0.3 0.2 0.1
A) mean : 1.9 ; standard deviation : 1.29
B) mean : 1.9 ; standard deviation 1.14
C) mean : 2 standard deviation 1.29
D) mean 2 standard deviation 1