In: Statistics and Probability
You may need to use the appropriate appendix table or technology to answer this question.
The following results are for independent random samples taken from two populations.
| Sample 1 | Sample 2 |
|---|---|
|
n1 = 20 |
n2 = 30 |
|
x1 = 22.9 |
x2 = 20.1 |
|
s1 = 2.6 |
s2 = 4.6 |
(a)
What is the point estimate of the difference between the two population means? (Use
x1 − x2.
)
(b)
What is the degrees of freedom for the t distribution? (Round your answer down to the nearest integer.)
(c)
At 95% confidence, what is the margin of error? (Round your answer to one decimal place.)
(d)
What is the 95% confidence interval for the difference between the two population means? (Use
x1 − x2.
Round your answers to one decimal place.)
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