The mean height of 9 students is 1.6 m. If one more student of height 1.56 m joins, the mean height of resulting number of students is :

1. 1.50 m

2. 1.956 m

3. 1.93 m

4. 1.596 m

By formula,

Mean = $\dfrac{\text{Total height}}{\text{No. of students}}$

Substituting values we get :

$\Rightarrow 1.6 = \dfrac{\text{Total height}}{9} \\[1em] \Rightarrow \text{Total height} = 9 \times 1.6 = 14.4 \text{ m}.$

Since, one more student of height 1.56 m joins.

New, total height = 14.4 + 1.56 = 15.96 m

Total students now = 10 (9 + 1).

Mean = $\dfrac{15.96}{10}$ = 1.596 m.

Hence, Option 4 is the correct option.