Explanation:
81
Mean of three numbers = 40 and lowest number = 19...[given]
Let the three observations be 19, x and y, respectively.
\(\text{Mean}=\frac{\text{Sum of all observations}}{\text{Total number of observations}}\)
\(\Rightarrow40=\frac{19+\text{x}+\text{y}}{3}\) [\(\because\) mean = 40, given]
\(\Rightarrow3\times40=19+\text{x}+\text{y}\)
\(\Rightarrow120=19+\text{x}+\text{y}\)
\(\Rightarrow\text{x}+\text{y}=120-19\)
\(\Rightarrow\text{x}+\text{y}=101\ ...(\text{i})\)
Since, 19 is the lowest observation.
Hence, for highest possible value of remaining two numbers, one must be 20.
Let x = 20
From Eq.(i), we get
20 + y = 101
y = 101 - 20
y = 81