Answer:
The mean length of time is 27 minutes.
Explanation:
To find the mean, we have to first calculate x and fx.
(0+12)/2=6
(12+24)/2=18
(36+48)/2=42
(48+60)/2=54
Now we have x, and f
Calculate fx by multiplying:
6×11=66
18×25=450
30×23=690
42×15=630
54×6=324
The mean is the sum of fx/sum of f
(66+450+690+630+324)/(11+25+23+15+6)=27
Hope this helps!