Answer:
See attachment for polygon
Step-by-step explanation:
Given
[tex]\begin{array}{cc}{Class} & {Frequency} & 78787 - 98786 & 9 &98787 - 118786 & 8 & 118787 - 138786 & 9 & 138787 - 158786 & 4 & 158787 - 178786 & 8 \ \end{array}[/tex]
Required
The frequency polygon
First, we calculate the midpoint of each class.
This is the average of the class limits
So, we have:
[tex]x_1 = \frac{78787 + 98786}{2} = \frac{177573}{2} = 88786.5[/tex]
[tex]x_2 = \frac{98787 + 118786}{2} = \frac{217573}{2} = 108786.5[/tex]
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[tex]x_5 = \frac{158787 + 178786}{2} = \frac{337573}{2} = 168786.5[/tex]
(138787 + 158786)/2
So, the table becomes:
[tex]\begin{array}{ccc}{Class} & {Frequency} & {x} &78787 - 98786 & 9 & 88786.5 & 98787 - 118786 & 8 & 108786.5 & 118787 - 138786 & 9 & 128786.5 & 138787 - 158786 & 4 & 148787.5 & 158787 - 178786 & 8 & 168786.5\ \end{array}[/tex]
See attachment for frequency polygon
