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:
Results can be 
Step-by-step explanation:
-The solution for this question:
is equal to 
× × × ×
-The calculation for :
<span>Just do 11-2 to get 9 so your answer is x to the 9th power where 9 is the exponent. Remember if u have to divide two numbers (same base or same number) and they have different exponents just subtract the exponents (top exponent minus bottom exponent)</span>
Answer:
339.42m
Step-by-step explanation:
Circumference of a circle=2x22/7x54
=339.42m
Answer:
28, 30, 32
Step-by-step explanation:
Three consecutive even numbers are three even numbers that are next to each other. For example, 2, 4 and 6 would be 3 consecutive even numbers.
With this sort of problem, you want to try to let each number be equal to one thing and then construct the same number of equations as you have variables:
Let's let,
Integer 1 = X
Integer 2 = Y
Integer 3 = Z
X + Y + Z = 90
We also know, that
Y = X + 2
And that
Z = X + 4
Now, we can sub these equations into the first equation. We do this so that we have everything represented as the same variable.
90 = X + (X+2) + (X+4)
90 = 3X + 6
84 = 3X
28 = X
So, the numbers are 28, 30 and 32
