Answer:
(3,2)
Step-by-step explanation:
2x+3y=12
substitute x with 3 because x=3
2(3)+3y=12
multiply
6+3y=12
(subtract 6 from both sides)
3y=6
(divide by 3 on both sides)
1y=2
x = 3 and y = 2
The answer is 45 because 2.50 times 18=45
Answer:
x=5
Step-by-step explanation:
cross multiply
45=9x
solve for x by dividing 9 to get x alone
5=x
The correct way 21/6 would be in decimal form is 3.5
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.
