Exam Review #3

Finding Mean, Median, and Mode from a Table

• If a class is made up of a range of numbers (ex. 0-3 hours), you must find the midpoint in order to eventually calculate the mean

  • Midpoint = (Max + Min)/2 -> (ex. 0+3/2 = 1.5)

• Multiply the midpoint by the frequency

• Find the total for the frequency and your previous calculation

• Divide the total you got from multiplying by the total frequency

Finding Mean, Median, and Mode from a Table

• To find the median

  • Step 1: take the total frequency and divide by 2

  • Step 2: go to the frequency column and begin counting until you reach that number

  • Step 3: Identify the class that number is in

• To find the mode, identify the class with the highest frequency

Mean, Median, & Mode

• Mean - the sum of all the data divided by the number of data points in the set

• Median - order all the data points from least to greatest and identify the middle number

  • If you have 2 numbers in the middle, add them together and divide by 2

• Mode - the value that shows up the most in the data set

Measures of Spread: Range, Standard Deviation & Variance

• Range = Max - Min

• Standard Deviation

  • Enter all your data into List 1

  • STAT -> CALC -> 1) 1-VAR STAT -> CALCULATE -> Sx

• Variance = Standard Deviation x Standard Deviation

Box & Whisker Plots

• To do a Box & Whisker Plot, you must find the Five Number Summary (Min, Q1, Med, Q3, Max)

  • Step 1: Enter all values in data set into List 1

  • Step 2: STAT -> CALC -> 1) 1-VAR STAT -> CALCULATE

  • Step 3: Scroll down until you find the five number summary