6.05 Correlations (Investigation)

Exercise 1

Think about, then discuss the strength and correlation of the following pairs of variables in the list below:

1. The floor space of an office and the number of desks that can fit.
2. The number of students on an excursion and the number of teachers supervising.
3. The number of text messages sent and the amount of prepaid credit remaining.
4. The distance driven by a car and the amount of fuel in the tank.
5. The height of a person and the number of hats they own.
6. A household electricity bill and the total income of the residents.
7. The amount of internet data and the age of the internet user.

Exercise 2

The average price of an airline ticket on a particular route between the years 2001 and 2009 is listed in the table below:

Average airline ticket prices (2001 to 2009)

• Present this data in a scatterplot using a spreadsheet tool or other technology.
• Fit a 'trendline'  to the data and display the equation of the line.
• Is this trendline accurate? Give reasons for your answer and comment on the factors that might be affecting the data.
• The below table highlights the prices between 2010 and 2014:

Average airline ticket prices (2010 to 2014)

• Plot the data on a separate graph and display the equation of the line.
• Compare the accuracy of this trendline to the one above.
• Using the equation of the line, predict the price of the airline ticket in the year 2015.