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:
yes the answer is never true
Step-by-step explanation:
as the correct answer is
Answer:
30 mins = 0.5 hours
4.5 miles/0.5 hours = your answer
Step-by-step explanation:
Sam divided a rectangle into 8 congruent rectangles that each have a area of 5 cm2. what is the area of the rectangle before it is divided?
Answer:
Step-by-step explanation:
Given:
Sam divided a rectangle into 8 congruent rectangles that each have an area of 
We need to find the area of the rectangle before Sam divided it.
The area of the rectangle before Sam divided is 8 times of the area of the congruent rectangles.
Area of the rectangle = 
Area of the congruent rectangle is
So the area of the rectangle is
Area of the rectangle = 
Area of the rectangle = 
Therefore the area of the rectangle before divided is
