Question: Cramer's Bar and Grille in Dallas can seat 130 people at a time. The manager has been gathering data on the number of minutes a party of four spends in the restaurant from the moment they are seated to when they pay the check. What is the mean number of minutes for a dinner party of four? What is the variance and standard deviation?
Number of Minutes Probability
60 0.05
70 0.15
80 0.20
90 0.45
100 0.10
110 0.05