Question

Average of four observations is22. if the first three numbers are 20,21 and 22 find the fourth observstions​

Answer 1

Answer:

Sum of 6 numbers =60×30=180

Sum of first 4 numbers =4×25=100

Sum of last 3 numbers =3×35=105

∴ Fourth number =(100+105)−180

=205−180

=25