Answer:
So the answer for this case would be n=30 rounded up to the nearest integer
Step-by-step explanation:
Information given
the margin of error desired
standard deviation from previous studies
The margin of error is given by this formula:
(a)
And on this case we have that ME =2 and we are interested in order to find the value of n, if we solve n from equation (a) we got:
(b)
The critical value for 99% of confidence interval now can be founded using the normal distribution. The significance level is
and the critical value would be
, replacing into formula (b) we got:
So the answer for this case would be n=30 rounded up to the nearest integer
Answer:
There are two real solutions if the radicand is
✔ positive.
There is one real solution if the radicand is
✔ zero.
There are no real solutions if the radicand is
✔ negative.
Step-by-step explanation:
ON MY DOG KIDS DIS RIGHT
We have the following equation:
x2 + y2 + 42x + 38y - 47 = 0
We rewrite the equation:
x2 + 42x + y2 + 38y - 47 = 0
x2 + 42x + y2 + 38y = 47
Rewriting we have:
x2 + 42x + (42/2) ^ 2 + y2 + 38y + (38/2) ^ 2 = 47 + (42/2) ^ 2 + (38/2) ^ 2
x2 + 42x + 441 + y2 + 38y + 361 = 47 + 441 + 361
Rewriting we have:
(x + 21) ^ 2 + (y + 19) ^ 2 = 849
The center of the circle is:
(x, y) = (-21, -19)
The radio is:
r = root (849)
r = (849) ^ 2
A circle of the same radius is given by:
x ^ 2 + y ^ 2 - 50x - 30y + 1 = 0
Let's check:
x ^ 2 - 50x + y ^ 2 - 30y + 1 = 0
x ^ 2 - 50x + y ^ 2 - 30y = - 1
x ^ 2 - 50x + (-50/2) ^ 2 + y ^ 2 - 30y + (-30/2) ^ 2 = - 1 + (-30/2) ^ 2 + (-50/2) ^ 2
x ^ 2 - 50x + (-50/2) ^ 2 + y ^ 2 - 30y + (-30/2) ^ 2 = - 1 + 225 + 625
(x-25) ^ 2 + (y-15) ^ 2 = 849
Answer:
(x + 21) ^ 2 + (y + 19) ^ 2 = 849
(x, y) = (-21, -19)
r = (849) ^ 2
x ^ 2 + y ^ 2 - 50x - 30y + 1 = 0
This is an expression if she only gets pedicure
y = 35
If she wants to get massage, multiply the cost for a minute with the number of minutes.
Find cost per minute first
cost = 50/20
cost = 2.5
So the expression would be
y = 35 + 2.5x
y = 2.5x + 35