Stanley planted a tree in his backyard. The manager of the plant nursery he purchased it from told Stanley that the tree would double in height every 4 years. If Stanley’s tree started out only 1.5 feet tall, how tall will it be in 20 years? Write an exponential equation of the general form [math]y = ab^t[/math], where [math]a[/math] is the initial value, [math]b[/math] is the base, [math]t[/math] is the time, and [math]y[/math] is the final value. Then use it to solve the problem.
[list=1] [*]Identify the known quantities. [*]Identify the unknown quantity or variable. [*]Create expressions and equations from the known quantities and variable(s). [*]Substitute the values into the general exponential formula, [math]y = ab^t[/math]. [*]Follow the order of operations to solve the problem. [*]Interpret the solution in terms of the context of the problem. [/list] This applet is provided by Walch Education as supplemental material for their mathematics programs. Visit [url="http://www.walch.com"]www.walch.com[/url] for more information on their resources.