Single Variable Statistics Day 1 Statistics Unit Algebra

Single Variable Statistics Day 1: Statistics Unit Algebra 1

Examples of Single-Variable Data - One Attribute • 10 students take a test and receive the following scores: 61, 72, 93, 100, 88, 97, 75, 99, 83, 93 • Weights of NFL football players: 210, 220, 207, 218, 187, 216, 247, 265, 236 •

Dot Plots •

Dot Plots • Features • Each dot represents a single observation • Dots are placed in columns based on categories • The heights of the dots in a column tell the relative frequency

Histograms •

Histogram • Features • Responses organized into groups call “bins” • The height of each bar represents frequency • bars touch each other

5 Number Summary • The 5 number summary is a way to describe data with 5 numbers • First data point (Min) • First Quartile (25% of data) - Q 1 • Second Quartile or Median (50% of data) - Q 2 • Third Quartile (75% of data) - Q 3 • Fourth Quartile (100% of data) - Q 4 (Max)

5 number summary: Practice Data: 77, 86, 99, 79, 87, 80, 94, 87 Step 1: Find Median or Q 2 Put all the data in order 77, 79, 80, 86, 87, 94, 99 Find the middle, since there are is an even number of data points, add the middle two and divide by 2 (86+87)/2 = 86. 5

5 Number Summary: Practice Step 2: Find Q 1 and Q 3 Split the Data into the Two halves 77, 79, 80, 86 87, 94, 99 Find the Median of Each Half (79+80)/2 = 79. 5 Q 1 = 79. 5 (87+94)/2 = 90. 5 Q 3 = 90. 5

5 Number Summary: Practice Step 3: Min and Max 77, 79, 80, 86, 87, 94, 99 When the data set is ordered the 1 st number is the min and the last number is the max Min = 77 Max = 99

Box Plot Box and Whiskers Plot

Box Plots • Features • Also known as “Box and Whiskers” • Uses 5 number summary to represent data • A dot is placed at min and max. A box is made with two sides at Q 1 and Q 3 and a line through the box at Q 2