What are vectors?
Vector operations
Indexing and filtering
Simple analysis
Summary
33. Exercise 6

## Instruction

Perfect. You're almost done! Just one more exercise.

## Exercise

The Versico management decided to reward the employees who have worked the hardest to improve their running performance over the last six months. Using the race_time vector, calculate the mean of all improved times for employees that improved their running times regarding their first running time (first_running_time vector).

### Stuck? Here's a hint!

If an employee improved their time, the difference between first_running_time and race_time for such an employee would be a positive number.

You'll need to use the following condition:

race_time[first_running_time - race_time > 0]
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