# From the following data relating to weights of 36 students in pounds, find out the following- obtain the range of weights of students-dinvide the range into appropriate no. of class intervals-find the no. of students whose weight is less than 145 pounds, more than 155 pounds, between 135 and 155 pounds138 164 150 144 168 126 142 135 140 131 144 125 138 176 163 135 161 145 149 157 146 119 150 165 150 156 154 140 146 128 173 115 135 176 167 187

Hey Vishva,

Check the solution for the above listed numerical.

 Weight (in pounds) Frequency (f) 115 119 125 126 128 131 135 138 140 142 144 145 146 149 150 154 156 157 161 163 164 165 167 168 173 176 187 1 1 1 1 1 1 3 2 2 1 2 1 2 1 3 1 1 1 1 1 1 1 1 1 1 2 1 N=$\Sigma f$=36

1. Range of the series = Highest value of the series-Lowest value of the series
= 187 pounds-115 pounds= 72 pounds

2.  Since, range is 72

Let the width of the class=10

Thus, no. of class intervals = $\frac{72}{10}=7.2\approx 8\phantom{\rule{0ex}{0ex}}\phantom{\rule{0ex}{0ex}}$

Hence, there will be eight (8) class intervals as follows:

 Class Intervals 110$-$120  120$-$ 130  130$-$ 140  140$-$ 150  150$-$ 160  160$-$ 170  170$-$ 180  180$-$ 190

3.
i. No. of students whose weight is less than 145 pounds = $\underset{w=115}{\overset{144}{\sum f}}$=16 students

ii.​No. of students whose weight is more than 155 pounds = ​$\underset{w=156}{\overset{187}{\sum f}}$=12 students

iii.​No. of students whose weight is between 135 and 155 pounds= = 15 students

Hope it helps!!

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