We can see that the lines intersect at (-5,3) on the graph, so that eliminates choices B and D. Both A and C say that the first line is y=x+8, which is true. A says that the second line is y+x=-2, and after isolating y, we get y=-x+2, which seems correct. Do the same for C, and you will find that it says the other equation is y=x-2, which is not true because it must have a negative slope. So your answer will be choice A.
Answer:
standard error = 2.11
Step-by-step explanation:
First we stablish the data that we have for each sample:
<u>Population 1</u> <u>Population </u>2
n₁ = 100 n₂ = 90
x¯1= 95 x¯2 = 75
σ₁ = 14 σ₂ = 15
To calculate the standard error of each sample we would use the formulas:
σ = σ₁/√n₁
σx¯2 = σ₂/√n₂
Now, in order to obtain the standard error of the differences between the two sample means we combine those two formulas to obtain this:
σx¯1 - σ x¯2 = √(σ₁²/n₁ + σ₂²/n₂ )
So as you can see, we used the square root to simplify and now we require the variance of each sample (σ²):
σ₁² = (14)² = 196
σ₂² = (15)² = 225
Now we can proceed to calculate the standard error of the distribution of differences in sample means:
σx¯1 - σx¯2 = √(196/100 + 225/90) = 2.11
This gives an estimate about how far is the difference between the sample means from the actual difference between the populations means.
Answer: 0 and 1, in that order
The numbers <u> 0 </u> and <u> 1 </u> are respectively the additive and multiplicative identities of rational numbers.
===========================================================
Explanation:
The additive identity is 0 because adding 0 to any number leads to the original number. For instance, 7+0 = 7. In general we can say x+0 = x or we could also say 0+x = x.
The multiplicative identity is 1 because multiplying 1 with anything leads to that original number. Example: 1*5 = 5 or 9*1 = 1. The general template is x*1 = x which is the same as saying 1*x = x.
These ideas not only apply to rational numbers, but to real numbers as well.
