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:
5/6 because 1/2 plus 1/3 is 5/6, meaning that B is the correct answer.
Hope this helps!
Answer:
there is a greater chance that she selects a even number because there are 4 even numbers and 3 odd numbers
Answer:
52
Step-by-step explanation:
56+(x+72) =180
180 because it is supplementary
Answer: 24% of the books read are magazine
Step-by-step explanation:sum of the books read is 20+12+18=50 books.
Therefore 12 of the books are magazine.
Then, 12 of 50 =24%( 12÷50)× 100/1 = 24%
