Answer:
common ratio: 1.155
rate of growth: 15.5 %
Step-by-step explanation:
The model for exponential growth of population P looks like: 
where
is the population at time "t",
is the initial (starting) population
is the common ratio,
and
is the rate of growth
Therefore, in our case we can replace specific values in this expression (including population after 12 years, and initial population), and solve for the unknown common ratio and its related rate of growth:
![P(t)=P_i(1+r)^t\\13000=2300*(1+r)^{12}\\\frac{13000}{2300} = (1+r)^12\\\frac{130}{23} = (1+r)^{12}\\1+r=\sqrt[12]{\frac{130}{23} } =1.155273\\](https://tex.z-dn.net/?f=P%28t%29%3DP_i%281%2Br%29%5Et%5C%5C13000%3D2300%2A%281%2Br%29%5E%7B12%7D%5C%5C%5Cfrac%7B13000%7D%7B2300%7D%20%3D%20%281%2Br%29%5E12%5C%5C%5Cfrac%7B130%7D%7B23%7D%20%3D%20%281%2Br%29%5E%7B12%7D%5C%5C1%2Br%3D%5Csqrt%5B12%5D%7B%5Cfrac%7B130%7D%7B23%7D%20%7D%20%3D1.155273%5C%5C)
This (1+r) is the common ratio, that we are asked to round to the nearest thousandth, so we use: 1.155
We are also asked to find the rate of increase (r), and to express it in percent form. Therefore we use the last equation shown above to solve for "r" and express tin percent form:

So, this number in percent form (and rounded to the nearest tenth as requested) is: 15.5 %
Answer:
3.149
Step-by-step explanation:
that is just the number pi never ends but in most math classes 3.149 is all yoi need
Answer:
$34.40
Step-by-step explanation:
this equation has 3 steps
1. to find out how much the dvds cost without any discount or tax: $40
2. the price of the dvds with the 20% discount, which can be found with cross-multiplication making the price after discount $32
3. the final price of the dvds with sales tax can be found also with cross-multiplication and the final answer would be 34.4
Step-by-step explanation:
2x²+2xy+yx+y²+2x²+2xy-yx+y²
2x²+2x²+2xy+2xy+yx-yx+y²+y²
2x²+2x²+2xy+2xy
4x²+4xy
Answer:
$37,650
Step-by-step explanation:
A=15000(1+0.0525)^18
A=15000(2.51)
A=37650