**Description**:

Annual retail gas prices since 1950, split by Leaded and Unleaded and adjusted for inflation.

**Data**:

http://www.eia.gov/totalenergy/data/annual/index.cfm

**Analysis:**

Gas prices have spiked sharply twice since 1949. Even though $3 per gallon sounds like a lot, when adjusted for inflation, it isn’t that bad when compared with some prior years. Both trend lines indicate that gas is getting cheaper over time; however, due to the wildly fluctuating prices of unleaded since just before 1980, the ‘least squares’ method of determining the trend line is problematic.

**Questions:**

- Why were the prices for leaded gasoline more stable than unleaded?
- Are we due for a major downward trend in prices?
- Is the amount of fuel consumption related to the retail price?

*Related*

To

**leave a comment** for the author, please follow the link and comment on their blog:

** Graph of the Week**.

R-bloggers.com offers

**daily e-mail updates** about

R news and

tutorials on topics such as:

Data science,

Big Data, R jobs, visualization (

ggplot2,

Boxplots,

maps,

animation), programming (

RStudio,

Sweave,

LaTeX,

SQL,

Eclipse,

git,

hadoop,

Web Scraping) statistics (

regression,

PCA,

time series,

trading) and more...

If you got this far, why not

__subscribe for updates__ from the site? Choose your flavor:

e-mail,

twitter,

RSS, or

facebook...

**Tags:** gas, gas prices, inflation, prices, statistics, trend