The following data give the amounts (in dollars) spent last month on food by 400 randomly selected families.

Food Expenditure                                                    Number of
(in dollars)                                                                    Families
200 to less than 500 .......................................................38
500 to less than 800 .....................................................105
800 to less than 1100 ...................................................130
1100 to less than 1400 ...................................................60
1400 to less than 1700 ...................................................42
1700 to less than 2000 ...................................................18
2000 to less than 2300 .....................................................7

Calculate the mean, variance, and standard deviation.