Answer:
d 20.4 years
Step-by-step explanation:
The equation is
A = Pe ^(rt)
We know that r = .034
We want the money to double so A = 2P
Substitute in
2P = P e ^(.034t)
Divide by P
2P/P = P/P e ^(.034t)
2 = e^ (.034t)
Take the natural log on each side
ln (2) = ln(e^ (.034t))
ln (2) = .034t
Divide by .034
ln (2) /.034 = .034t/.034
ln (2)/.034 = t
20.3867 =t
Let the number of reptiles on endangered list be 'x'
2x + 16=158
2x=158-16
2x=142
x=71
So there are 71 reptiles on the endangered list
Given:
t1 = 3.6 h
t2 = 4.5 h
x = speed of boat
y = speed of water
Required:
a) Expression of distance traveled with moving water with 3.6h
Expression of distance traveled with moving water with 4.5h
b) Solve for y
c) Percent of boat's speed is the water current
Solution:
Working formula: distance = velocity*time
a) For travelling downstream, we get the equation
d = (x +y)*3.6
For travelling upstream, we get the equation
d = (x-y)*4.5
b) Setting the distance as equal for travelling upstream or downstream, we arrive at the equation of
(x+y)*3.6 = (x-y)*4.5
3.6x + 3.6y = 4.5x - 4.5y
8.1y =0.9x
y = x/9
c) percentage = 1/9*100% = 11.1%
<em>ANSWERS: a) d = (x+y)*36; d = (x-y)*4.5
</em> <em>b) y = x/9
</em> <em>c) 11.1%</em>
Answer:
The required confidence inteval = 94.9%.
Step-by-step explanation:
Confidence interval: Mean ± Margin of error
Given: A confidence interval for the true mean diameter of all oak trees in the neighbourhood is calculated to be (36.191, 42.969).
i.e. Mean + Margin of error = 42.969 (i)
Mean - Margin of error = 36.191 (ii)
Adding (i) and (ii), we get
Margin of error = 42.969-39.58 [from (i)]
= 3.389
Margin of error = 
here n= 25 
i.e.
Using excel function 1-TDIST.2T(2.054,24)
The required confidence inteval = 94.9%.
