Question

                                     

Purpose: To ensure that you can get StatCrunch up and running, download and open a data file, create graphical and numeric output, and transfer the output into Word.

1. Open the data file Soda.csv in Excel. The file contains survey responses from 339 adults. Variables are ‘Soda’ = the % of daily fluid intake due to soda, ‘Diet’ = whether or not the individual is on a diet, ‘Gender’ = the gender of the individual, and ‘Age’ = the age in years of the individual.

1. Which of the variables are categorical?

2. Which of the variables are numeric?

3. What are the scales of measurement of the variables?

2. Open the data file StocksTbills1960-2000.csv in StatCrunch. The file contains percent returns for stocks ‘stock’ and US Treasury bills ‘tbill’ for each year from 1960 to 2000.

1. Use StatCrunch to produce a dotplot of ‘tbill’ and paste it

                                                                  here

2. Use StatCrunch to calculate the sample mean of ‘tbill’ and paste the output

                                                                  here.

3. Submit the assignment by uploading this document.

Answer 1

(a) Diet is  categorical variable, as it has two level whether or not ( the individual is on a diet)

Gender is a categorical variable, as it will take two values male and female

A categorical variable is one that has two or more categories, but there is no intrinsic ordering to the categories.  

Categorical variables can be further categorised into ordinal and nominal variables.

A categorical variable whose categories can be meaningfully ordered is called ordinal.

It does not matter which way the categories are ordered in tabular or graphical displays of the data -- all orderings are equally meaningful.

(b) Soda and Age are numeric variables

The values of a numeric variable are numbers.

They can be further classified into discrete and continuous variables.

A variable whose values are whole numbers (counts) is called discrete.

A variable that may contain any value within some range is called continuous.