Given:
The mean number of emails adele received during a week was 51.
The numbers received for the six days were 39, 57, 70, 45, 71, 32.
To find:
The number of emails received on the seventh day.
Solution:
Let x be the number of emails received on the seventh day.
We know that,
[tex]\text{Mean}=\dfrac{\text{Sum of observations}}{\text{Number of observations}}[/tex]
[tex]51=\dfrac{314+x}{7}[/tex]
Multiply both sides by 7.
[tex]357=314+x[/tex]
Subtract 314 from both sides.
[tex]357-314=x[/tex]
[tex]43=x[/tex]
Therefore, she received 43 emails on the seventh day.
