Find out the Range coefficient of the range marks number of students
20-29 8
30-39 12
40-49 20
50-59 7
60-69 3​

0.4494

Step-by-step explanation:

Given :

marks number of students

20-29 8

30-39 12

40-49 20

50-59 7

60-69 3​

The range Coefficient is obtained thus :

Range Coefficient = (Xm - Xl) / (Xm + Xl)

Where ;

Xm = Mid value of highest class = (60+69)/2 = 64.5

Xl = Mid value of lowest class = (20+29)/2 = 24.5

Range Coefficient = (64.5 - 24.5) / (64.5 + 24.5)

Range Coefficient = 40 / 89 = 0.4494

y + 11 = (1/4)(x + 16)

step-by-step explanation:

2.2°  

step-by-step explanation:

let θ = the angle of elevation.

tanθ =77/2020

tanθ = 0.038 12

      θ = tan⁻¹0.038 12

      θ = 2.2°