The table shows the time taken by Luis to run 100 metres during his training sessions. After 3 attempts, Luis wanted to improve his average time taken by 1.6 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) |
17 |
17 |
23 |
? |
Total time that Luis took for the first 3 attempts
= 17 + 17 + 23
= 57 s
Average time that Luis took for the first 3 attempts
= 57 ÷ 3
= 19 s
New average time that Luis took for the 4 attempts
= 19 - 1.6
= 17.4 s
Total time that Luis took for the 4 attempts
= 4 x 17.4
= 69.6 s
Time that Luis should run in the 4
th attempt in order for him to make the improvement
= 69.6 - 57
= 12.6 s
Answer(s): 12.6 s