Z-scores

Two swimmers, Bert and Ernie, from different teams, wanted to find out who had the fastest time for the 50 meter freestyle when compared to his team. Which swimmer had the fastest time compared to his team?

Swimmer Time (seconds) Team Mean Time Team Stand. Dev.

Bert 26.2 27.2 0.8

Ernie 27.3 30.1 1.4

Bert's z-score: ________________________

_________________ stand. dev. ________________ (below/above) his team's mean time

Ernie's z-score: ________________________

_________________ stand. dev. ________________ (below/above) his team's mean time

Conclusion: ______________________ had the fastest time when compared to his team.

Next Find the z-score of the value x if x is:

Two standard deviations below the mean

1.4 standard deviations above the mean

3 standard deviations above the mean

Located on the mean