1. Warm up
How do outliers effect the mean, median, mode, and range in a set of data?
Based on your answer to number one, which do you think would be the best way to measure a set of data when outliers are present?

2. Warm up
If the outlier is high or low it causes the mean to be high or low and makes it unreliable
Outliers effect the range because the highest and the lowest numbers are being used.
(We will not get an accurate idea of what the actual range is if outliers are present).
Outliers have very little effect on mode or median
The median is the best, since the mode doesn’t actually tell us much about the all of the data.

3. Introduction to statistics
October 22, 2013

4. What is statistics? Almost everyday you are exposed to statistics
Consider the following examples:
“A survey of traffic deaths during this past Memorial Day weekend shows a 36% decrease in fatalities compared with last year.”
“More than three fourths of all college seniors in the United States complete at least one internship by graduation and 55% participate in two or more.”

5. These statements are based on the collection of data
Data: consists of information coming from observations, counts, measurements, or responses.
When we collect data we usually display it in the form of a graph or a table

6. In this unit we are going to learn many different ways to display data graphically
Line graph
Scatter plot
Circle graph

7. More graphs
Histogram
Bar graph
Box and whisker plot

8. We will also be looking a different kinds of tables
Stem and Leaf plot
Two way table
Frequency table

9. Types of data spread
Symmetric or mound shaped
Uniform
Skewed left

10. After looking at the graph that is skewed left, What do you think a graph that is “skewed right” will look like?
Skewed left
Skewed right

11. Statistics is the science of collecting, organizing, analyzing, and interpreting data in order to make decisions.
There are two types of data sets you will use when studying statistics:
Population: the collection of all outcomes, responses, measurements, or counts that are of interest.
Sample: is the subset of a population.

12. Types of data
When doing a study, it is important to know the kind of data involved.
The nature of the data you are working with will determine which statistical procedure can be used.

13. Data sets can consist of two types of data
Qualitative data: consist of attributes, labels, or non-numerical entries. (sometimes also called: “categorical”)
Deals with descriptions.
Data can be observed but not measured.
Colors, textures, smells, tastes, appearance, beauty, etc.
Qualitative → Quality

14. 2. Quantitative data: consist of numerical measurements or counts.
And….
2. Quantitative data: consist of numerical measurements or counts.
Deals with numbers.
Data which can be measured.
Length, height, area, volume, weight, speed, time, temperature, humidity, sound levels, cost, members, ages, etc.
Quantitative → Quantity 

15. Qualitative data vs. Quantitative data

16. Qualitative data vs. Quantitative data

17. Qualitative data vs. Quantitative data

18. Determine if the following are qualitative or quantitative:
1. The age of your car  
2. The number of hairs on your knuckle.  
3. The softness of a cat.  
4. The color of the sky.  
5. The number of pennies in your pocket.