Wednesday, March 24,2010

Yesterday in Algebra 1, we worked on connecting grow factor with growth rate. The growth factor is the number in an exponential function which the previous result is multiplied by in order to get the result for the next interval of the function. For example, in the equation y=100(2.2)* 2.2 is the growth factor because it is the number that *(x) is multiplied by to get the next sum in the function. Once we learned about growth factor, we learned about growth rate. The growth rate is the percent of increase in an exponential function, and it is sometimes given in place of the growth factor. When the population is growing 3% a year, 3% is the growth factor. Growth factor and growth rate are easily interchangeable. When the growth factor is 1.23, the growth rate is 23%. This is because when changing growth rate to growth factor you simply put the percentage in decimal form and add one to it (because you add the current amount to the growth rate when you are solving a function). When the money within a bank account is 4,000, and grows 7% a year, all you have to do to find the amount in it after the first year is do 4000 x 1.07. 7% is really 0.07, and once you add one to include the 4000, you get 1.07 as the growth factor. Switching from the growth factor to the growth rate is just as easy as the oppisite. Subtracting 1 from the growth factor and putting the remaining decimal into a percent is all it consists of. When the growth factor is 1.80, you do 1.80-1=.80 .80=80% and you find that the growth rate is eighty percent when the grwoth factor is 1.80. Growth factor and growth rate are simply connected. By Kate M :-)