<h3>Answer: B) 31.348</h3>
======================================
Work Shown:
We will never use the alpha = 0.05 value when computing the test statistic. So we can ignore alpha for this particular problem.
-------
n = 40 is the sample size.
s = 2.6 is the sample standard deviation
= sigma = 2.9 is the population standard deviation (ie the claimed standard deviation for all the pay phones)
Test Statistic for chi-square

Answer: f=3
Step-by-step explanation:
The intervals means that angle f is between the quadrant 1.
where x+y=90
Step-by-step explanation:
2(2x + 1) = 3(x - 4)
4x+2=3x-12
4x-3x=--12-2
x=14
Let's start by understanding that the graph is a linear line. We have a common difference if 4.5 for every 10x we have more.
We can start by finding the gradient, using rise over run. Let's take (10, 4.5) and (20, 9)
Our rise is 9 - 4.5 = 4.5 and our run is 10. Then, our gradient becomes 4.5/10 = 0.45
Now, we can substitute points using the point-slope form.
y - 4.5 = 0.45(x - 10)
y - 4.5 = 0.45x - 4.5
Hence, our line becomes y = 0.45x and you can verify by substituting in points from the table.