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.
Many lines do. One of them would be y = 2x
Yes it will. A 2 quart pitcher is equal to 8 cups, and since 1/4 and 1/3 are less it can still hold it.
Step-by-step explanation:
there should be at least
Answer:
The value of rate of which the base is changing
= - 3 
Step-by-step explanation:
Area = 20 
height = 4 cm


we know that area of the triangle is given by



B = 10 cm
Rate of change of area is given by
![\frac{dA}{dT} = \frac{1}{2} [B\frac{dH}{dt} + H \frac{dB}{dt} ]](https://tex.z-dn.net/?f=%5Cfrac%7BdA%7D%7BdT%7D%20%3D%20%5Cfrac%7B1%7D%7B2%7D%20%5BB%5Cfrac%7BdH%7D%7Bdt%7D%20%2B%20H%20%5Cfrac%7BdB%7D%7Bdt%7D%20%5D)
4 = 0.5 [10 × 2 + 4
]
= - 3 
This is the value of rate of which the base is changing.