The population size of the above data is 8, that is N=8 The mean (average) = (<span>12 +10+ 11.5 +11.5 +12 +9 +9 +11)/8 = 10.75 Standard deviation is the square root of variance, it is one of the measures of central dispersion, that is a measure of by how much the values in the data set are likely to differ from the mean. In this case, Standard deviation, </span>s= √(∑(x-m)²)/(n-1) = 1.172 Thus, best approximation of the standard deviation is 1.17
So you have four different toppings and two different sauces. This means you have four outcomes for the marinara sauce and four more for the alfredo sauce adding up a total of eight outcomes.