Please help with these questions and show how u found them i will mark you brainliest
2 answers:
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Answer:
A sample of 179 is needed.
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 .
That is z with a pvalue of , so Z = 1.44.
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.
A previous study found that for an average family the variance is 1.69 gallon?
This means that
If they are using a 85% level of confidence, how large of a sample is required to estimate the mean usage of water?
A sample of n is needed, and n is found for M = 0.14. So
Rounding up
A sample of 179 is needed.
y - y₁ = m(x - x₁)
y - 1 = 1³/₅(x - 2) Point - Slope Form
y - 1 = 1³/₅(x) - 1³/₅(2)
y - 1 = 1³/₅x - 3¹/₅
+ 1 + 1
y = 1³/₅x - 2¹/₅ Slope - Intercept Form
-1³/₅x - y = 1³/₅x - 1³/₅x - 2¹/₅
-1³/₅x - y = -2¹/₅
-1(-1³/₅x - y) = -1(-2¹/₅)
-1(-1³/₅x) + 1(y) = 2¹/₅
1³/₅x - y = 2¹/₅ Standard Form
1³/₅(0) - y = 2¹/₅
0 - y = 2¹/₅
-y = 2¹/₅
-1 -1
y = -2¹/₅ Y - Intercept
(x, y) = (0, -2¹/₅)