Question

The mean temperature for the first 4 days in January was -4°C. The mean temperature for the first 5 days in January was -6°C. What was the temperature on the 5th day? Pls help

Answer 1

-14°C

Explanation:

Given that,

The mean temperature for the first 4 days in January was -4°C.

The mean temperature for the first 5 days in January was -6°C.

Mean = sum of observations/no. of observations

For first 4 days,

`-4=(S_4)/(4)\\\\S_4=-16\ ...(1)`

For first 5 days,

`-6=(S_4+T)/(5)\\\\S_4+T=-30\ ..(2)`

Let the temperature on 5th day is T. So,

Put S₄ = -16 in equation (2).

-16 + T = -30

T = -30+16

T = -14°C

So, the temperature on the 5th day is -14°C.