Answer:
The mean monthly salary of these 100 graduates is $2388.5
Step-by-step explanation:
First, lets make all of the salaries a set, so:
S = {S1,S2,S3,S4,S5}
where
S1 = {1001-1400}
S2 = {1401-1800}
S3 = {1801-2200}
S4 = {2201-2600}
S5 = {2601-3000}
Each element S1,S2,..,S5 will have it's own mean, that will be the upper range + lower range divided by 2.
So
M(S1) = (1400+1001)/2 = 2401/2 = 1200.5
M(S2) = (1401+1800)/2 = 3201/2 = 1600.5
M(S3) = (1801+2200)/2 = 4001/2 = 2000.5
M(S4) = (2201+2600)/2 = 4801/2 = 2400.5
M(S5) = (2601+3000)/2 = 5601/2 = 2800.5
To find the approximate mean, now we calculate a weigthed mean between M(S1),M(S2),...,M(S5)
So the mean will be
M = (M(S1)+11*M(S2)+14*M(S3)+38*M(S4)+36*M(S5))/100
M = 238850/100
M = 2388.5
So the mean monthly salary of these 100 graduates is $2388.5