<h3>Answer: B) 31.348</h3>
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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.
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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
Variance is the standard deviation squared but we're not going to use that now. Let's first calculate the mean:
mean = (17+13+13+22+11+20)/6 = 16.
Now for each value, let's see how far it is from this mean. We'll square these distances and average them. That's our variance.
17 distance 1 squared = 1
13 distance 3 squared = 9
13 distance 3 squared = 9
22 distance 6 squared = 36
11 distance 5 squared = 25
20 distance 4 squared = 16
Now average these outcomes:
variance = (1+9+9+36+25+16)/6 = 16.
So the variance by coincidence is the same as the mean.
Answer C is your answer.
Answer:
C
Step-by-step explanation:
The big triangle and small triangles are similar so their corresponding sides are in proportion.
x/15 = 15/9
x= 15*15/9
x=25
