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:
When we have a discount of X% of the original price, the new price is calculated as:
New price = (original price) - (original price)*(X%/100%)
In our case, let's define:
P = original price of the fishing pole
f = price of the fishing pole after the discount
X% = 20%
Then the equation for the price of the fishing pole is:
f = P - P*(20%/100%) = P - P*0.2 = P*(1 - 0.2) = P*0.8
f = 0.8*P
This means that the price after the discount is 0.8 times the original price.
Answer:
c = 22
Step-by-step explanation:
x^2 + c = 103 so if x is either + or - 9, x^2 = 81 so...
81 + c = 103
c = 22
Answer:
the answer is B
Step-by-step explanation:
^^
There is no solution since 5 doesn't equal 45
