Final answer:
To find the proportion of first serves in the men’s tournament that have a speed faster than 119.1 mph, calculate the z-score and find the corresponding proportion in the standard normal distribution. The proportion is approximately 0.35, or 35%.
Step-by-step explanation:
To find the proportion of first serves in the men’s tournament that have a speed faster than 119.1 mph, we need to calculate the z-score and then find the corresponding proportion in the standard normal distribution.
First, we calculate the z-score using the formula: z = (x - mean) / standard deviation.
Plugging in the values, we get: z = (119.1 - 120.8) / 4.4 = -0.3864.
Next, we look up the corresponding proportion using a z-table or calculator. The proportion of first serves with a speed faster than 119.1 mph is approximately 0.35, or 35%.