Fastball Speed and Statistics

The video tutorial explains how Major League Baseball records pitch data, focusing on fastball speeds from the 2009 season. It covers the use of normal distribution to analyze these speeds, including calculating z-scores and probabilities for specific speed ranges. The tutorial also demonstrates how to identify the slowest 10% of fastballs using statistical methods.

What is the primary focus of the data recorded by Major League Baseball?

• Stadium attendance

• Player salaries

• Every pitch thrown in every game

• Team win-loss records

Who compiled the data about pitches thrown by 20 starting pitchers during the 2009 MLB season?

• Jim Albert

• Michael Johnson

• John Doe

• Jane Smith

What types of pitches are included in the dataset?

• Only fastballs

• Curveball, changeup, slider, etc.

• Only curveballs

• Only sliders

What is the mean speed of the fastballs according to the normal distribution model?

• 95.0 mph

• 92.12 mph

• 88.7 mph

• 90.5 mph

What is the standard deviation of the fastball speeds in the normal model?

• 3.5 mph

• 1.8 mph

• 2.43 mph

• 4.0 mph

How is the z-score calculated for a pitch speed?

• x plus mu divided by sigma

• x minus mu divided by sigma

• x times mu divided by sigma

• x divided by mu minus sigma

What is the z-score for a pitch with a speed of 85.3 mph?

• -1.5

• -2.81

• 0.5

• 2.81

What function is used to find the probability of fastball speeds within a certain range?

• normalpdf

• standard deviation

• normalcdf

• inverse norm

What is the probability of a fastball having a speed between 89 mph and 90.8 mph?

• 0.1939

• 0.5000

• 0.2500

• 0.7500

What is the probability of a fastball having a speed below 89 mph?

• 0.7500

• 0.2500

• 0.0996

• 0.5000