31. I'm not positive but give it a shot if it is wrong message me back!
Answer:
17
Step-by-step explanation:
I think 17
I believe the problem ask for s which is the standard
deviation. We must recall that the formula for z statistic is stated as:
z = (x – x over bar) / s
Where,
z = z statistic = 2.5
x = sample value or sample score = 102
x over bar = the sample mean or sample average = 100
s = standard deviation = unknown
Rewriting the equation in terms of s:
s = (x – x over bar) / z
Substituting the given values into the equation:
s = (102 – 100) / 2.5
s = 0.8
Therefore the standard deviation s is 0.8
Using the z-distribution, it is found that:
- The 95% confidence interval is of -1.38 to 1.38.
- The value of the sample mean difference is of 1.74, which falls outside the 95% confidence interval.
<h3>What is the z-distribution confidence interval?</h3>
The confidence interval is:
In which:
- is the difference between the population means.
In this problem, we have a 95% confidence level, hence, z is the value of Z that has a p-value of , so the critical value is z = 1.96.
The estimate and the standard error are given by:
Hence the bounds of the interval are given by:
1.74 is outside the interval, hence:
- The 95% confidence interval is of -1.38 to 1.38.
- The value of the sample mean difference is of 1.74, which falls outside the 95% confidence interval.
More can be learned about the z-distribution at brainly.com/question/25890103
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A number less than 15 is 5