My Math Forum > Math Average of percentage

 Math General Math Forum - For general math related discussion and news

 January 16th, 2017, 04:01 AM #1 Newbie   Joined: Jan 2017 From: iraq Posts: 1 Thanks: 0 Average of percentage Dear friends, I know this question is very simple but I will ask it hope not to misunderstand, recently I involved in a test which one of the questions like below: a company revenue growth percentage were 30%, 10% and 90% within 3 years continuously what is the percentage of average yearly growth. I know average is adding all numbers and divide by the number of years, but in the test there were not answer options like that. the answer options were 25, 20, 35, 40. I don't remember exactly.
 January 16th, 2017, 04:47 AM #2 Math Team     Joined: Jul 2011 From: Texas Posts: 2,947 Thanks: 1555 I'd say the correct choice is about 40%. Coming to a solution is not as easy as one would think ... Let $R$ represent the initial revenue ... Year 1 growth of 30% yields a new revenue of $1.3 \cdot R$ Year 2 growth of 10% yields a new revenue of $1.1 \cdot (1.3 \cdot R) = 1.43 \cdot R$ Year 3 growth of 90% (wow!) yields a new revenue of $1.9 \cdot (1.43 \cdot R) = 2.717 \cdot R$ So, for the 3 year period, $R$ increased by a factor of $2.717$ Let $a$ be the average yearly growth factor ... $a^3 = 2.717 \implies a \approx 1.3954 \implies$ average yearly growth percentage is about 39.54%. To check, say $R=\$100$growth rate of revenue about 39.54% per year ...$\$100 \cdot 1.3954^3 = \$271.70\$

 Tags average, percentage

 Thread Tools Display Modes Linear Mode

 Similar Threads Thread Thread Starter Forum Replies Last Post neil1975 Elementary Math 2 February 25th, 2016 06:27 AM Apple30 Elementary Math 4 January 22nd, 2015 05:04 PM Mr Davis 97 Physics 1 April 26th, 2014 11:58 PM SidT Elementary Math 5 August 17th, 2008 02:16 AM ritchie888 Algebra 1 June 18th, 2008 02:31 PM

 Contact - Home - Forums - Cryptocurrency Forum - Top