The table shows the time taken by Pierre to run 100 metres during his training sessions. After 3 attempts, Pierre wanted to improve his average time taken by 1.4 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) |
23 |
23 |
23 |
? |
Total time that Pierre took for the first 3 attempts
= 23 + 23 + 23
= 69 s
Average time that Pierre took for the first 3 attempts
= 69 ÷ 3
= 23 s
New average time that Pierre took for the 4 attempts
= 23 - 1.4
= 21.6 s
Total time that Pierre took for the 4 attempts
= 4 x 21.6
= 86.4 s
Time that Pierre should run in the 4
th attempt in order for him to make the improvement
= 86.4 - 69
= 17.4 s
Answer(s): 17.4 s