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Introduction to Statistics

Statistics Lab

Using Packages of Colored Candies

Purpose of Statistics

Describe a set of numbers and then make accurate

inferences (a.k.a. educated guesses) about that

group of data based on incomplete information

Statistics Involves

- Gathering Data
- Organizing Data (sometimes pictorially)
- Analyzing Data

The Problems

- Although candies are sold by weight rather than

volume, how many candies can I expect when I open

a 1.69 oz package?

2) How likely is it that the numbers of colors in

each package occurred randomly?

Gathering Data

- Open your package of Candy
- Separate, count and record the number of each

color in the package.

Organize the Data

- Open an EXCEL Spreadsheet Document

Organize the Data

Continue with the entire classs information.

Analyzing Data problem 1

Although candies are sold by weight rather

than volume, how many candies can I expect when I

open a 1.69 oz package?

What do I need to know?

Analyzing Data

Measures of Central Tendency

Mean

Average

Median

Number in the Middle

Mode

Number used Most

Analyzing Data

Measures of Variability

Range

Spread

Standard Deviation

The average distance each piece of

data is from the mean

Analyzing Data

Analyzing Data

Use the Insert gt Function capabilities of Excel

to do the calculations

Analyzing Data

What do each of these calculations mean?

- Supposed I only get 22 candies. Am I being

cheated in quantity?

2) How about 74 candies?

Analyzing Data problem 2

How likely is it that the numbers of colors in

each package occurred randomly?

How can I test this?

Analyzing Data using an EXCEL function

ChiTest A test for independence which returns the

probability that your observed data and your

expected data are related.

In this case we are seeking an answer to How

likely is it that the candies counted were

packaged strictly by chance?

Analyzing Data

Hypothesis The observed number of colored

candies per package is not significantly

different than the number found if the candies

were packaged purely at random.

Analyzing Data

The CHITEST returns a value between 0 and 1. The

closer the number is to 1, the more likely your

hypothesis is true.

Back to EXCEL

Analyzing Data

Use EXCEL CHITEST function to determine the

probability that your bag of candies were

packaged according to these percentages.