The given graph represents the monthly salaries (in ₹) of workers of a factory.

Using graph answer the following:

(a) the total number of workers.

(b) the median class.

(c) the lower-quartile class.

(d) number of workers having monthly salary more than or equal to ₹6,000 but less than ₹10,000.

(a) From the graph, the cumulative frequency at ₹12,000 is 75.

Hence, the total number of workers = 75.

(b) By formula,

Median = $\dfrac{N + 1}{2}$

Total workers = 75

$\dfrac{75 + 1}{2} = \dfrac{76}{2} = 38$

From table,

36 to 55 worker lies in the class 6000 - 8000.

Thus, 38th worker lies in the class 6000 - 8000.

Hence, the median class = 6000 – 8000.

(c) Lower quartile = $\dfrac{N + 1}{4} = \dfrac{76}{4} = 19$

From table,

11 to 20 worker lies in the class 2000 - 4000.

Thus, 19th worker lies in the class 2000 - 4000.

Hence, the lower-quartile class = 2000 – 4000.

(d) From table,

Number of workers having salary less than ₹ 10,000 = 70

Number of workers having salary less than ₹ 6,000 = 35

Number of workers in this range = 70 − 35 = 35 workers.

Hence, the number of workers having monthly salary more than or equal to ₹ 6,000 but less than ₹ 10,000 = 35.