Data are collected on the weekly expenditures of a sample of urban households on food (including restaurant expenditures). The data, obtained from diaries kept by each household, are grouped by number of members of the household. The expenditures are as follows:

a. Compute the mean expenditure separately for each of the five groups.
b. Combine the five data sets into a single data set and then compute the mean expenditure.
c. Describe a method by which the mean for the combined data set could be obtained from the five individual means.
d. Describe the relation (if any) among the mean expenditures for the five groups.

1 member: 2 members: 129 116 122 70 141 102 120 75 114 81 106 95 3 members: 4 members: 139 25 93 15 158 114 108 5+ membe 121 128 19 140 206 11 104 109 135 136 67 62 168 128 131 118 80 53 99 68 76 55 84 77 7 4084 65 67 183 94 98 85 81 67 69 119 10 94 9492 79 99 17 45 86 100 116 125 82 142 294 85 191 100 116 111 106 99 132 62 129 91