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.
10w^7 is the answer I’m pretty sure
-100 feet ( below means negative )
The answer choice that correctly calculates and interprets the standard deviation of the sum, S = X + Y is D. Sigma Subscript s = 0.8; companies A and B can expect the total weight of packages to vary by approximately 0.8 ounces from the mean.
<h3>What does the standard deviation means?</h3>
A standard deviation means the all measure of how dispersed the data is in relation to the mean. It should be noted that low standard deviation means that the data are clustered around the mean, and the high standard deviation means that the data are more spread out.
In this case, the answer choice that correctly calculates and interprets the standard deviation of the sum, S = X + Y is the sigma Subscript s = 0.8; companies A and B can expect the total weight of packages to vary by approximately 0.8 ounces from the mean.
In conclusion, the correct option is D.
Learn more about standard deviation on:
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Answer:
Step-by-step explanation:
1) Expand by distributing terms.
2) Simplify 4*3x to 12x.
3) Simplify 4*2y to 8y.
<u>Therefor, the answer is </u><u>12x + 8y.</u>
