Answer: 168cm^2
Step-by-step explanation:
lets split this into two shapes:
a rectangle and a triangle
Formulas:
rect: b * h
Tri: (b*h)/2
Solve:
12 * 10 = 120
(12*8)/2 = 48
120 + 48 =
168cm^2
Answer:
The minimum sample size that should be taken is 62.
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 
.
So it is z with a pvalue of 
, so 
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.
If we want to be 90% confident that the sample mean is within 1 word per minute of the true population mean, what is the minimum sample size that should be taken
This is n when 
. So
The minimum sample size that should be taken is 62.
Answer:
10 times greater hun
Step-by-step explanation:
70000 times 10 equals 700000
first speed --- x mph
return speed -- x+16 mph
6/x + 6/(x+16) = 1
times each term by x(x+16)
6(x+16) + 6x = x(x+16)
x^2 + 4x - 96 = 0
(x-8)(x+12) = 0
x = 8 or x is a negative
her first speed was 8 mph
her return speed was 24 mph
check:
6/8 + 6/24 = 1 , that's good!
25 anything raised to zero equals one
