Answer:
0.5s
Step-by-step explanation:
His initial mean would be calculated by:
His minimum race time = 19.8s
The maximum race time = 19.8 + 5.6 = 25.4s
Since the mode is also 25.4, there are 2 25.4s races.
Since the median is 23.8s and the number of race times is even, the final race time can be calculated by:
25.4- 23.8s = 1.6s
23.8-1.6 = 22.2s
So the race times are 19.8s, 22.2s, 25.4s and 25.4s.
This means that his initial mean was (19.8+22.2+25.4+25.4)/4 = (42+50.8)/4= 92.8 /4 = 23.2s
With the new race time, the equation will change to (92.8+25.7)/(4+1)= 118.5/5= 23.7s
So the mean change would be 23.7 - 23.2 = 0.5 s.
Hope this helps!
