whatever% of anything is just (whatever/100) * anything.
800+1250+120+625+65 gives us 2860.
now, she doesn't get any commission from the 2000, just the surplus, the 860.
how much is 15% of 860? well is just (15/100) * 860.
Answer: 2500 years
Step-by-step explanation:
I'm not quite sure if I'm doing this right myself but I'll give it a shot.
We use this formula to find half-life but we can just plug in the numbers we know to find <em>t</em>.

We know half-life is 5730 years and that the parchment has retained 74% of its Carbon-14. For
let's just assume that there are 100 original atoms of Carbon-14 and for A(t) let's assume there are 74 Carbon-14 atoms AFTER the amount of time has passed. That way, 74% of the C-14 still remains as 74/100 is 74%. Not quite sure how to explain it but I hope you get it. <em>h</em> is the last variable we need to know and it's just the half-life, which has been given to us already, 5730 years, so now we have this.

Now, solve. First, divide by 100.

Take the log of everything

Divide the entire equation by log (0.5) and multiply the entire equation by 5730 to isolate the <em>t</em> and get

Use your calculator to solve that giant mess for <em>t </em>and you'll get that <em>t</em> is roughly 2489.128182 years. Round that to the nearest hundred years, and you'll find the hopefully correct answer is 2500 years.
Really hope that all the equations that I wrote came out good and that that's right, this is definitely the longest answer I've ever written.
9514 1404 393
Answer:
y = 3.02x^3 -5.36x^2 +5.68x +8.66
Step-by-step explanation:
Your graphing calculator (or other regression tool) can solve this about as quickly as you can enter the numbers. If you have a number of regression formulas to work out, it is a good idea to become familiar with at least one tool for doing so.
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If you're trying to do this by hand, the x- and y-values give you 4 equations in the 4 unknown coefficients.
a·1^3 +b·1^2 +c·1 +d = 12
a·3^3 +b·3^2 +c·3 +d = 59
a·6^3 +b·6^2 +c·6 +d = 502
a·8^3 +b·8^2 +c·8 +d = 1257
Solving this by elimination, substitution, or matrix methods is tedious, but not impossible. Calculators and web sites can help. The solutions are a = 317/105, b = -75/14, c = 1193/210, d = 303/35. Approximations to these values are shown above.
Answer:
1.05
Step-by-step explanation: