The table shows the time taken by Will to run 100 metres during his training sessions. After 3 attempts, Will wanted to improve his average time taken by 1.3 seconds by running faster in the 4
th attempt. How fast should he run in the 4
th attempt in order for him to make the improvement?
Attempt |
1st |
2nd |
3rd |
4th |
Time taken (in seconds) |
18 |
23 |
19 |
? |
Total time that Will took for the first 3 attempts
= 18 + 23 + 19
= 60 s
Average time that Will took for the first 3 attempts
= 60 ÷ 3
= 20 s
New average time that Will took for the 4 attempts
= 20 - 1.3
= 18.7 s
Total time that Will took for the 4 attempts
= 4 x 18.7
= 74.8 s
Time that Will should run in the 4
th attempt in order for him to make the improvement
= 74.8 - 60
= 14.8 s
Answer(s): 14.8 s