# Khilona earned scores of 97, 73 and 88 respectively in her first three examinations. If she scored 80 in the fourth examination, then her average score will be

(a) increased by 1

(b) increased by 1.5

(c) decreased by 1

(d) decreased by 1.5

**Solution:**

Khilona earned scores of 97, 73 and 88 in her first three examinations.

She scored 80 in the fourth examination

We have to determine the change in average score of Khilona.

We know, __mean__ = sum of observations/number of observations

Considering first three scores,

Sum of observations = 97 + 73 + 88

= 258

Number of observations = 3

Mean = 258/3

= 86

Considering four scores,

Sum of observation = 97 + 73 + 88 + 80

= 258 + 80

= 338

Number of observations = 4

Mena = 338/4

= 84.5

Difference between mean = 86 - 84.5

= 1.5

Therefore, the mean is decreased by 1.5

**✦ Try This: **Find the mode of the data 3, 4, 1, 4, 5, 2, 4, 3, 5

**☛ Also Check: **NCERT Solutions for Class 7 Maths Chapter 3

**NCERT Exemplar Class 7 Maths Chapter 3 Problem 14**

## Khilona earned scores of 97, 73 and 88 respectively in her first three examinations. If she scored 80 in the fourth examination, then her average score will be (a) increased by 1 (b) increased by 1.5 (c) decreased by 1 (d) decreased by 1.5

**Summary:**

Khilona earned scores of 97, 73 and 88 respectively in her first three examinations. If she scored 80 in the fourth examination, then her average score will be decreased by 1.5

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