Following table shows a frequency distribution for the speeds of cars passing througha particular spot on a highway:

Draw a histogram and frequency polygon representing the above data.

Explanation

Adding two more class intervals, namely `20-30` and `100-110,` each with frequency `0`, we have the frequency distribution table as under:

We represent the class intervals along the `x`-axis on a suitable scale and the corresponding frequencies along the `y`-axis on another suitable scale. We construct rectangles with class intervals as the bases and the respective frequencies as the heights.
Thus, we obtain the histogram, shown below. We take the imagined classes `20-30` and `100 110`, each with frequency `0`.
Now, we plot the points `A(25, 0), B(35, 3), C(45, 6), D(55, 25), E(65, 65), F(75, 50), G(85, 28), H(95, 14)` and `I(105, 0).` Joining these points in pairs successively, we obtain the required frequency polygon `ABCDEFGHI,` as shown below.