Chapter 2 Section 2.1: Organizing qualitative data Section 2.2: Organizing quantitative data Section 2.3: skip Section 2.4: Misrepresentations of data

Qualitative vs. Quantitative (Different tools for different data) Question 1: Type of skin cancer – A: Qualitative – B: Quantitative

Qualitative vs. Quantitative (Different tools for different data) Question 1: Type of skin cancer – A: Qualitative – B: Quantitative Question 2: Quarterly profit – A: Qualitative – B: Quantitative

Qualitative vs. Quantitative (Different tools for different data) Question 1: Type of skin cancer – A: Qualitative – B: Quantitative Question 2: Quarterly profit – A: Qualitative – B: Quantitative Question 3: Customer satisfaction – A: Qualitative – B: Quantitative

Qualitative vs. Quantitative (Different tools for different data) Question 1: Type of skin cancer – A: Qualitative – B: Quantitative Question 2: Quarterly profit – A: Qualitative – B: Quantitative Question 3: Customer satisfaction – A: Qualitative (poor, moderate, high) – B: Quantitative (1,2,3,4,5,6,7,8,9,10) It isn’t always totally clear!

Frequency: A fancy word for “count”

Distribution: A way to describe how likely certain values are to be observed.

Frequency: A fancy word for “count” Distribution: A way to describe how likely certain values are to be observed. Frequency distribution: A list tabulating the number of occurrences for each category

Frequency: A fancy word for “count” Distribution: A way to describe how likely certain values are to be observed. Frequency distribution: A list tabulating the number of occurrences for each category Relative frequency distribution: A frequency distribution that uses proportions instead of counts.

Which is a relative frequency table? Statistics 108 students’ class standings (n=79) Class standing Freshmen Sophomore Junior Senior A B

These graphs are: (A)bar graphs (B)histograms Which graph is the relative frequency graph? (A) top graph (B) bottom graph

The only difference between a frequency bar graph and a relative frequency bar graph is the labeling of the y-axis. (Likewise for histograms.) Relative frequency saves the reader calculations Frequency graphs tell the reader the actual counts.

A pie chart of the data

Use the below data to calculate degrees of the sophomore slice. (A)12 degrees (B)0.15 degrees (C)15 degrees (D)55 degrees

Histograms Histograms are for quantitative data “Classes” or “bins” are which data are grouped into. Upper and lower limit for each class/bin is subjective. Goal: Summarize data, but leave some detail.

Weights of 87 sparrows (grams) Stem-and-leaf plot In the below software’s stem-and-leaf plot, the decimal point is at the | Displays vary slightly across statistical software 23 | | | | | | | 0 30 | 31 | 0

Determine the original data set: (The decimal point is 1 digit(s) to the right of the |) 0| | | | | 00 (A)0.2, 0.3, 0.4, 0.5, 0.8, 0.8, 0.9, 1, 1, 1, 1.1, 1.3, 1.4, 1.4, 1.4, 1.4, 1.5, 1.7, 1.8, 2, 2 (B)2, 3, 4, 5, 8, 8, 9, 10, 10, 10, 11, 13, 14, 14, 14, 14, 15, 17, 18, 20, 20 (C)234, 5889, 1000, 1001, 1003, 1004, 1004, 1004, 1004, 1004, 1587, 200 (D)0.234, , , 1.578, 2.00

Create a stem-and-leaf plot for values: 24,25,26,29,29,30,31,31,35,36,36 2 | 4 2 | | | | |

Bad graphs…