To construct an interval estimate for the difference between the ...

[aabwk4]

To construct an interval estimate for the difference between the means of two populations when the standard deviations of the two populations are unknown and it can be assumed the two populations have equal variances, we must use a t distribution with (let n1 be the size of sample 1 and n2 the size of sample 2)
 a. (n1 + n2) degrees of freedom.
  b. (n1 + n2 - 1) degrees of freedom.
  c. (n1 + n2 - 2) degrees of freedom.
  d. (n1 - n2 + 2) degrees of freedom.

Question 2

When developing an interval estimate for the difference between two population means with sample sizes of n1 and n2,
 a. n1 must be equal to n2.
  b. n1 must be smaller than n2.
  c. n1 must be larger than n2.
  d. n1 and n2 can be of different sizes.

[sailorcrescent]

Answer to Question 1

c

Answer to Question 2

d

[aabwk4]

Excellent

[mjenn52]

Gracias!