Question

At the first game of the Major League Baseball season, a statistician keeps track of every pitch that a player throws during the game. The statistician reported that the mean pitch speed was 80 miles per hour (mph) and the standard deviation of the serve speeds was 10 mph. Assume that the statistician also gave us the information that the distribution of pitch speeds was mound- shaped and symmetric. What percentage of the player's serves were between 80 mph and 100 mph

Answer 1

Answer:

47.725%

Step-by-step explanation:

We solve using z score formula

z = (x-μ)/σ, where

x is the raw score

μ is the population mean = 80 mph

σ is the population standard deviation = 10 mph

For x = 80 mph

z = 80 - 80/10

z =0

Probability value from Z-Table:

P(x = 80) = 0.5

For x = 100 mph

z = 100 - 80/10

z = 2

Probability value from Z-Table:

P(x = 100) = 0.97725

Probability of the player's serves thay were between 80 mph and 100 mph is calculated as:

P(x = 100mph) - P(x = 80 mph)

= 0.97725 - 0.5

= 0.47725

The percentage of the player's serves that were between 80 mph and 100 mph is calculated as:

Converting to percentage:

0.47725 × 100 = 47.725%