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.
Answer:
The answer is 20
Step-by-step explanation:
(Edge2020)
Answer: The area of the lake is actually 182 square miles 1 inch represents one side 3 miles long the other side is also 3 miles. 3×3=9 square miles. 1 Square Inch on the map represents 9 Square Miles.
Step-by-step explanation: If the area on the map is 18 square inches, and each square inch represents 9 square miles, multiply 18×9=182 to get the area of that big lake.
Answer:
r = 5sec(θ)
Step-by-step explanation:
The usual conversion is ...
y = r·sin(θ)
x = r·cos(θ)
__
The second of these can be used here.
r·cos(θ) -5 = 0
r·cos(θ) = 5
r = 5/cos(θ) = 5sec(θ)
A suitable polar equation is ...
r = 5sec(θ)
$0.80 = 1 pound
5.5 pounds in total
5.5x$0.80= $4.40
brainliest answer ?