Answer: 18.7
Step-by-step explanation:
Find the lengths of AB, BC, and CA
AB = 
= 5
≈ 7.1
BC = 
= 5 ≈ 7.1
CA = 
= 2
≈ 4.5
7.1 + 7.1 + 4.5 = 18.7
Let us solve this system of equations by using the elimination method. Adding the 2 equations, we get
9x + 5y - 9x + 4y = -33 + 6
9y = -27
y = -3
Substituting this value of y in the first equation, we get
-9x + 4(-3) = 6
-9x - 12 = 6
9x + 12 = -6
9x = -18
x = -2
Therefore, x = -2, and y = -3. Hope this helps! If you have any questions, feel free to ask.
Answer:
6 < 2n = 4
Step-by-step explanation:
ig
Answer:
84
Step-by-step explanation:
x = number of girls
The total for boys is 2x * 81 and for girls it would be 90x
Therefore, the equation goes like this:
2x * 81 + 90x
Then simplify, and set to equal 3x...
3x = 252
Which is the same as
x = 84
Thank me later :)
Answer:
a.1.90 years
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.
In this question:
So
So the correct answer is:
a.1.90 years
