Answer:
0.25
Step-by-step explanation:
3/12 = 1/4
1÷4= 0.25
Answer:
440
Step-by-step explanation:
55x8. 8x5=40 carry the 4. 8x5=40+4=44 so it is 440
Answer:
We need to sample at least 1069 parents.
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.
How many parents do you have to sample?
We need to sample at least n parents.
n is found when 
. So
Rounding up
We need to sample at least 1069 parents.
Answer:
infinitely many
Step-by-step explanation:
Add 12-y to both sides of the second equation to put it into standard form like the first equation:
y +(12 -y) = (x -12) +(12 -y)
12 = x - y . . . simplify
x - y = 12 . . . . second equation in standard form
We see this is identical to the first equation. That means every solution of the first equation is also a solution of the second equation. There are infinitely many solutions.
Answer:
B
Step-by-step explanation:
