Question

12. The marks obtained by a set of students in an examination are given below.
Marks
5
10
15
20
25
30
Number of students
6
4
6
12
x
4
Given that the mean mark of the set is 18, calculate the numerical value of x.
ICS​

Answer 1

Answer:

Mean = 18

Mean = ∑ fiXi / ∑fi

     18 = 520 + 25x / 32 + x

 576 + 18x = 520 + 25x

 56             = 7x

x = 8    

*Refer to attached Sheet for the Tabular form

c8ea358eec28705df832276717d59640.xlsx

Answer 2

Answer:

• The marks obtained by a set of students in an examination all given below:
• Given that the mean mark of the set of students is 18, calculate the numerical value of x.

Step-by-step explanation:

Calculation of Mean :

∴ Mean = Σfx/Σf

∴ 18 = (520 + 25x)/32 + x

⇒ 576 + 18x = 520 + 25x

⇒ 7x = 56

⇒ x = 8.