Question

Consider the following results for independent random samples taken from two populations.

Sample 1	Sample 2
n 1 = 10	n 2 = 30
x 1 = 22.5	x 2 = 20.5
s 1 = 2.5	s 2 = 4.6

1. What is the point estimate of the difference between the two population means (to 1 decimal)?
2. What is the degrees of freedom for the t distribution (round down your answer to nearest whole number)?
3. At 95% confidence, what is the margin of error (to 1 decimal)?
4. What is the 95% confidence interval for the difference between the two population means (to 1 decimal)? Use z-table. If your answer is negative value, entre minus (-) sign.
   ( ,  )

Answer 1

a) The point estimate of the difference between the two population means

= 22.5 - 20.5

= 2

b-d)