In the 2012 Olympics, the mean finishing time for the men’s 100-meter dash finals was 10.10 seconds and the standard deviation was 0.72 second. Usain Bolt won the gold medal, with a time of 9.63 seconds. Assume a normal distribution. What was Usain Bolt’s z-score?

Write the known information about the distribution.

Substitute these values into the formula for calculating z-scores.

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