False Sometimes its different for all
Answer:
Equations: 
number of chickens = 52
number of goats = 28
Step-by-step explanation:
Given: A small ranch has chickens and goats
Total number of heads = 80
Total number of legs = 216
To find: number of chickens and goats
To draw: the graph
Solution:
Let x denotes number of chickens and y denotes number of goats.
According to the question,

From (i), put
in (ii)

Put
in equation (i)

So,
number of chickens = 52
number of goats = 28
-8 -8 = -16
You add -8 to -8
Answer:
A sample of 18 is required.
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 Z-table as such z has a p-value of
.
That is z with a pvalue of
, so Z = 1.88.
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.
A previous study indicated that the standard deviation was 2.2 days.
This means that 
How large a sample must be selected if the company wants to be 92% confident that the true mean differs from the sample mean by no more than 1 day?
This is n for which M = 1. So



Rounding up:
A sample of 18 is required.
Answer:
4π cm
Step-by-step explanation:
The length of an arc of a circle with radius r and central angle θ is given by ...
s = rθ
where θ is in radians.
Here, your arc measures 60° = π/3 radians, so the arc length is ...
s = (12 cm)(π/3) = 4π cm