### One-Way Airplane Ticket from Phoenix to San Diego (to Phoenix) From \$53.96 to \$78.20

One-way airplane ticket to San Diego, California, from Phoenix, Arizona, during May of 2004.

```                        Base Fare:  \$53.96
Tax (US domestic percentage 7.5%):  \$ 4.04
Fare:  \$58.00

Tax (US domestic segment):  \$ 6.20
Fee (passenger facility charges):  \$ 9.00
Fee (September 11th security):  \$ 5.00

Total Per Passenger:  \$78.20
```

Based upon the printed receipt, `\$4.04` is `7.5%` of `\$53.96`. Prove it.

```   What is 7.5% of \$53.96?

n = 7.5% * \$53.96

n = 7.5(.01) * \$53.96

n = .075 * \$53.96

n = \$4.04700
```

Notice that `\$4.04700` rounded to the nearest cent (i.e. hundredth) is `\$4.05`, yet the airline rounded down.

The September 11th security fee of `\$5.00` is ```6.4% of the total fare. Let's see why. ```

``` 5 is what percent of \$78.20 5 = n * \$78.20 5 n * \$78.20 ------ = ------------ 78.20 \$78.20 0.0639 = n 0.0639 * 100 = 6.39% (approximately 6.4%) As proven earlier, \$4.04 is 7.5% of \$53.96. Let's check our work. \$4.04 is 7.5% of what? \$4.04 = 7.5% * n \$4.04 = 7.5(.01) * n \$4.04 = .075 * n \$4.04 .075 * n ----- = -------- .075 .075 \$53.8666 = n (rounded \$53.87) Oops... the fare was \$53.96; we are off by nine cents. Recall, our answer to the question "what is 7.5% of \$53.96?" come out to be \$4.047. Let's use \$4.047 instead of \$4.04 and answer the question "\$4.047 is 7.5% of what?" \$4.047 ------ = \$53.9600 (or \$53.96) .075 ```
``` Creator: Gerald D. Thurman [gthurman@gmail.com] Created: 11 March 2005 <!-- document.writeln("<b>URL:</b> " + document.URL + "<br />"); document.writeln("<b>Last Modified:</b> " + document.lastModified + "<br />"); //--> + added RoadHacker Nanofoo section This work is licensed under a Creative Commons License. RoadHacker Nanofoo RoadHacker flew to San Diego with the intentions of renting a car and roadtripping home to Tempe; however, the San Diego car rental places would not rent him a car due to lack of a major credit-card. The following pictures were taken from the plane. Tovrea Castle (Phoenix) San Diego: downtown ... ships ... sprawl Salton Sea: desert to farmlands ... farmlands ... farmlands to desert downtown Phoenix Update::08 November 2005 ScienceDaily.com:: Environmental Scientists Propose Chemical Solution To Cleaning California's Salton Sea During Spring Break 2003, RoadHacker visited the Salton Sea. ```