Please solve it urgently The following data give the amounts (in dollars) spent

Question

Please solve it urgently

The following data give the amounts (in dollars) spent last month on food by 400 randomly selected families. Food Expenditure (in dollars) Number of Families 200 to less than 500 38 500 to less than 800 105 140 800 to less than 1100 1100 to less than 1400 1400 to less than 1700 1700 to less than 2000 2000 to less than 2300 50 42 17 Calculate the mean, variance, and standard deviation. Carry out all calculations exactly, round to 2 decimal places the final answers where it is necessary. Mean = Variance Standard deviation = 1

Explanation / Answer

x.   f x * f

350 - 38 - 13300

650 - 105 - 68250

950 - 140 - 133000

1250 -. 50 - 62500

1550. -. 42 - 65100

1850 - 17 - 31450

2150 - 8 - 17200

Sum - 400 - 390810

Mean = (13300 + 68250 + 133000 + 62500 + 65100 + 31460 + 17200) / 400 = 977.03

Variance =( (350 - 977.03)^2 * 38 + (650 - 977.03)^2 * 105 + (950 - 977.03)^2 * 140 + (1250 - 977.03)^2 * 50 + (1550 - 977.03)^2 * 42 + (1850 - 977.03)^2 * 17 + (2150 - 977.03)^2) * 8 / 400 = 205852.06

Standard deviation = sqrt(205852.06) = 453.71

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