Answer:
The diameter decreases at a rate of 0.053 cm/min.
Step-by-step explanation:
Surface area of an snowball
The surface area of an snowball has the following equation:

In which d is the diameter.
Implicit differentiation:
To solve this question, we differentiate the equation for the surface area implictly, in function of t. So

Surface area decreases at a rate of 3 cm2/min
This means that 
Tind the rate (in cm/min) at which the diameter decreases when the diameter is 9 cm.
This is
when
. So




The diameter decreases at a rate of 0.053 cm/min.
Answer:
20
Step-by-step explanation:
2x - 5 = x + 15
2x - x = 5 + 15
x = 20
Answer:
A sample size of at least 228 must be needed.
Step-by-step explanation:
We are given that in the latest survey by the National Association of Colleges and Employers, the average starting salary was reported to be $61,238. Assume that the standard deviation is $3850.
And we have to find that what sample size do we need to have a margin of error equal to $500 with 95% confidence.
As we know that the Margin of error formula is given by;
<u>Margin of error</u> = 
where,
= significance level = 1 - 0.95 = 0.05 and
= 0.025.
= standard deviation = $3,850
n = sample size
<em>Also, at 0.025 significance level the z table gives critical value of 1.96.</em>
So, margin of error is ;
= 15.092
Squaring both sides we get,
n =
= 227.8 ≈ 228
So, we must need at least a sample size of 228 to have a margin of error equal to $500 with 95% confidence.
A. all real numbers for both
Explanation:
Domain is the x-values. Since the graph goes forever horizontally, any x-value is on the graph.
Range is the same but with y-values. If the graph went on further than what the picture shows, then it also would show that every y value is on the graph
hope this helps