The inter quartile range for the given ogive is :

1. 42

2. 32

3. 44

4. 54

No. of terms (N) = 80

Lower quartile (Q₁) = $\dfrac{N}{4}$ th term

= $\dfrac{80}{4}$ = 20 th term = 10.

Upper quartile (Q₃) = $\dfrac{3N}{4}$ th term

= $\dfrac{3 \times 80}{4} = \dfrac{240}{4}$ = 60 th term.

1. From point A = 60. Draw a line parallel to x-axis touching the graph at B.

2. From point B, draw a line parallel to y-axis touching graph at C.

From graph, point C = 52.

∴ Upper quartile (Q₃) = 52

By formula,

Inter quartile range = Upper quartile - Lower quartile

= Q₃ - Q₁

= 52 - 10 = 42.

Hence, Option 1 is the correct option.