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: The average velocity of the object over the time interval [3,6] is 20.
Step-by-step explanation:
Since we have given that
s(3) = 156
s(6) = 216
We need to find the average velocity over the time interval [3,6].
So, average velocity becomes

Hence, the average velocity of the object over the time interval [3,6] is 20.
Answer:
___________
| |
Step-by-step explanation:
It is 48 by 12
Answer:
The answer is below
Step-by-step explanation:
Let x represent the number of single cone ice cream and let y represent the number of double cone ice cream.
Since the vendor stocks a maximum of 70 single cones and a maximum of 45 double cones. hence:
0 < x ≤ 70, 0 < y ≤ 45 (1)
The vendor expects to sell no more than 50 ice creams, hence:
x + y ≤ 50
Plotting the constraint using geogebra online graphing tool, we can see that the solution to the problem is at (5, 45)
Since the vendor sells single-cone ice-creams for $3 and double-cone ice-creams for $4.50, hence:
Revenue = 3x + 4.5y
At the point (5, 45), the revenue is:
Revenue = 3(5) + 4.5(45) = $217.5
The answer is A because since the balance is 325 and you are trying to find what it was before you deposited