The new mean is 66.09
Explanation:
Mean weight of 20 students = 65kg
One student with 88kg entered the room.
New mean = ?
[tex]\frac{x_1+x_2+....+x_2_0}{20} = 65[/tex]
[tex]\frac{x_1+x_2+....+x_2_0 + 88}{21} = ?[/tex]
The above equation can further be written as:
[tex]x_1 + x_2 +....+x_2_0 = 65 X 20\\\\x_1 + x_2 +....+x_2_0 = 1300[/tex]
New mean = [tex]\frac{1300 + 88}{21}[/tex]
= 66.09
Therefore, the new mean is 66.09