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
+ added RoadHacker Nanofoo section

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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.

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.