Answer:
24.8 mins
Step-by-step explanation:
We'll begin by generating a table indicating the time mark (mid time) for the 50 people.
This is illustrated below
Time > timemark > frequency
0 – 10 > 10/2 = 5 > 5
10 – 20 > (10+20)/2 = 15 > 15
20 – 30 > (20+30)/2 = 25 > 13
30 – 40 > (30+40)/2 = 35 > 10
40 – 50 > (40+50)/2 = 45 > 7
The mean time for the 50 people is given by:
Mean = summation (mid time x frequency) / total frequency
Mean = [5x5 + 15x15 + 25x13 + 35x10 + 45x7] / 50
Mean = [25 + 225 + 325 + 350 + 315] / 50
Mean = 1240 / 50
Mean = 24.8 mins
