Answer:
OR 
Step-by-step explanation:
So first you find the difference between the new cost and the old cost:
450 - 370 = 80
So the increase was 80.
When you write it as a fraction you write the increase ( 80 ) over the starting cost ( 370 ).
Thus the answer becomes
But you can always reduce it to its lowest terms thus:
HOPE THIS HELPED
Answer:
24.6 < μ < 27.2
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.
The lower end of the interval is the sample mean subtracted by M. So it is 25.9 - 1.3 = 24.6 pounds.
The upper end of the interval is the sample mean added to M. So it is 25.9 + 1.3 = 27.2 pounds.
So the correct answer is:
24.6 < μ < 27.2
There are two ways to do this but the way I prefer is to make one of the equations in terms of one variable and then 'plug this in' to the second equation. I will demonstrate
Look at equation 1,
this can quite easily be manipulated to show
.
Then because there is a y in the second equation (and both equations are simultaneous) we can 'plug in' our new equation where y is in the second one
which can then be solved for x since there is only one variable
and then with our x solution we can work out our y solution by using the equation we manipulated
.
So the solution to these equations is x=-2 when y=6
Answer:
7
Step-by-step explanation:
Answer:
168
Step-by-step explanation:
