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: The standard deviation was calculated incorrectly.
Step-by-step explanation:
- The standard deviation measures the dispersion of the data values from the mean value.
It cannot be negative , because it is the square root of the variance .
We add all squared deviations from the data points away from the mean and (then divide it by the number of data values) to evaluate variance.
Since , any squared number cannot give a negative result.
⇒ Standard deviation cannot be negative.
⇒The standard deviation was calculated incorrectly.
Rest other things (given in options) can not be interpreted on the basis of given information.
Answer:
114, and 115
Step-by-step explanation:
114+115 = 229
Answer:
1
Step-by-step explanation:
(-4) - (-6) - (2-1)
-4 + 6 -2 +1
1
Answer:
Hope 292.5 is right.
Step-by-step explanation:
First thing, multiply the triangles base and height which will give you 143 then divide it by two which is 71.5. Then to the parallelogram which is base times height which is 117. Moving on to the trapezoid, meanin one-hal times height times first base plus second base giving you 104. Finally, add'em up, giving you a total of 292.5.