X=1/12 .........................................
Answer:
Step-by-step explanation:
The formula for compound annual interest is A = P(1 + r)t where
A = Accumulated or final amount (double $500 = $1000)
P = Principal or original amount ($500)
r = Rate as a decimal (0.08)
t = Time in years
1000 = 500(1 + 0.08)t
2 = 1.08t
Take the logarithm of both sides. I prefer the natural logarithm ln, but if you're more comfortable with base 10 logs they will work just as well
ln(2) = ln(1.08t)
ln(2) = t*ln(1.08)
t = ln(2)/ln(1.08)
t = 9.0065 years
Check: 500*1.089.0065 = $1000
36%=36/100=0,36
0,36•47677= 17 163,74
So there's around 17 164 species treatensd with extinction
Answer:
D. 31
Step-by-step explanation:
We have that to find our 
level, that is the subtraction of 1 by the confidence interval divided by 2. So:
Now, we have to find z in the Ztable as such z has a pvalue of 
.
That is z with a pvalue of 
, so Z = 1.96.
Now, find the margin of error M as such
In which 
is the standard deviation of the population and n is the size of the sample.
A previous study indicated that the population standard deviation is 2.8 days.
This means that 
How large a sample must be selected if the company wants to be 95% confident that the true mean differs from the sample mean by no more than 1 day?
This is n for which M = 1. So
Rounding up, at least 31 people are needed, and the correct answer is given by option D.
Answer:
[μ-error, μ + error]
[14000- 3000, 14000 + 3000]
Step-by-step explanation:
We write it how an interval, where the center of the interval is the mean, thus
[μ-error, μ + error]
First we calculate the mean
μ = (11000+17000)/2
μ = $14000
And the error is the absolute value of the difference between the mean an either extreme values
error = |14000 -17000| = |14000 - 11000| = 3000
Then
[14000- 3000, 14000 + 3000]
