SOLUTION: Table 1 shows the scores made on an intelligence test by a group of children who participated in the experiment. (a) Construct a frequency distribution table (Hint: class width

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Question 1182259: Table 1 shows the scores made on an intelligence test by a group of children who participated in
the experiment.
(a) Construct a frequency distribution table (Hint: class width is 10).
(b) Find the mean and standard deviation for this grouped data.
114 115 113 112 113 132 130 128 122 121 126 117
115 88 113 90 89 106 104 126 127 115 116 109
108 122 123 149 140 121 137 120 138 111 100 116
101 110 137 119 115 83 109 117 118 110 108 134
118 114 142 120 119 143 133 85 117 147 102 117
Answer by math_tutor2020(3817) (Show Source):
You can put this solution on YOUR website!

I'll do part (a) to get you started.

Sort the data values from smallest to largest. I strongly recommend using spreadsheet software, though you can sort by hand if you want.
This is what the sorted list looks like (there are 12 rows and 5 columns to give 12*5 = 60 items total; the order is from left to right, top to bottom)

83 85 88 89 90
100 101 102 104 106
108 108 109 109 110
110 111 112 113 113
113 114 114 115 115
115 115 116 116 117
117 117 117 118 118
119 119 120 120 121
121 122 122 123 126
126 127 128 130 132
133 134 137 137 138
140 142 143 147 149

The smallest value in this list is 83. Let's say each class starts at a multiple of 10, meaning that the closest value is 80

The range represents a width of 10. We could also say where x is a whole number. I'll go with this second version.

Count how many values are between 80 and 89, inclusive of both endpoints. You should count out 4 values and they are: 83,85,88,89

That means 4 is the frequency for this first class.

The frequency for the class is 1 because there's only one value in this range (the value 90)

Then for the class there are the values {100,101,102,104,106,108,108,109,109} which means the frequency for this class is 9.

Keep going with this process until you have this table

Class Frequency
80 to 89 4
90 to 99 1
100 to 109 9
110 to 119 23
120 to 129 11
130 to 139 7
140 to 149 5