Here is the question
The Swedish krona's currency has gone down by half during a 15-year period. Calculate the yearly procentual decline, if we assume the decline has been the same each year.
This is what I have come up with;
x^15 = ?
How do I write "a half" when I don't know what it is a half of?
The answer to this should be 4,5%
It stands for the Natural Log. Essentially, what power do you have to raise e, which is Euler's constant to, to get a number.
Natural logarithm - Wikipedia, the free encyclopedia
That's how you solve for the percentage in this problem. I worked it through, and it comes up to t he answer you give.
Do you want to research the link, or have me finish the math?
No logs needed . . .
The original amount is irrelevant.The Swedish krona's currency has gone down by half during a 15-year period.
Calculate the yearly percent decline,
if we assume the decline has been the same each year.
Let = annual rate of devaluation (percent).
Suppose the original value of the krona is monetary units.
In the first year, the krona has lost of its value.
. . Its value is: . units.
In general, in years, the value is reduced to: . units.
We are told that in 15 years, the value is: .
There is our equation: .
Divide by . (see?)
Take the 15th root: .
. . and we have: .
This is an A grade question (the VERY EASY one) and the answer to the first question was extremly easy. Let me show you;
A prognosis says that our electicity use will quadruple in the next 25 years. By how many percent per year will the electicity usage go up?
We know we have 25. We know it will quadruple (4) but we don't know how many percent it will go up with.
x^25 = 4
(x^25)1/25 = 4^1/25
x = 4^1/25
x = 1,057 which is almost 5,7%
Thats how easy it should be :P
Pretty awsome to see how good I could get at math though.. I really look up to you guys and girls
Please help me someone Im stuck!
[The Swedish krona's currency has gone down by half during a 15-year period. Calculate the yearly procentual decline, if we assume the decline has been the same each year.]
So here is what I have tried;
x^15 = x / 2
2x^15 = x
2 = x / x^15
2 = x^14
2^1/14 = x
x = 1.057
x^15 = 0.5
x = 0.5^1/15
x = 0,9548
Wrong.... but It could be right because x (is almost) = 0,955. Might be that
1-0.955 = 0.045 = 45%.
aha.. that would be that the diffirence, thus the DECLINE would be 45% not the incline. The diffirence might be calculated from the aspects of 100%... someone please correct me on this one