Answer:
A sample of 217 is needed.
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 the population standard deviation is $3,750 how large should the sample be if margin of error is $500
We have that
.
We need a sample of n, and n is found when
. So






Rounding up
A sample of 217 is needed.
Answer:
10 people can go to the amusement park
Step-by-step explanation:
363 - 5.50 = 357.5
357.5 / 35.75 = 10
The equations are:
x + y = 200
x = y - 40; substituting x from this equation to the first:
y - 40 + y = 200
2y = 240
y = 120
Corresponding value of x:
x = 120 - 40
x = 80
The solution to this system is (80, 120)
Y=1/4x+5/2 is your equation of the line.
Answer:
y=21
Step-by-step explanation: