Diana invested $3000 in a savings account for 3 years. she earned $450 in interest over that time period. what interest rate did she earn? use
the formula /=prt to find your answer, where is interest, pis principal, ris rate and tis time. enter your solution in decimal form rounded to
the nearest hundredth. for example, if your solution is 1296, you would enter 0.12.

Step-by-step explanation:

we know that

The simple interest formula is equal to

where

A is the Final Interest Value

P is the Principal amount of money to be invested

r is the rate of interest  

t is Number of Time Periods

in this problem we have

substitute in the formula above

solve for r

the answer is b

step-by-step explanation:

we have

using a graphing tool

see the attached figure

this is a quadratic equation (vertical parabola) open up

the vertex is a > vertex

the domain of the function is all real > interval (-∞,∞)

the range of the function is the > [-6.125,∞)

the function has two x->   and

the function is increasing over the > (0.25,∞)

the function is decreasing over the > (-∞,0.25)