Determine Whether the Samples Are Independent or Dependent $x _ { 1 } = 958$

Multiple Choice

Determine whether the samples are independent or dependent.
-Independent samples from two different populations yield the following data. $x _ { 1 } = 958$ , $x _ { 2 } = 157 , s _ { 1 } = 77$ , $\mathrm { s } _ { 2 } = 88$ . The sample size is 478 for both samples. Find the $85 \%$ confidence interval for $\mu _ { 1 } - \mu _ { 2 }$ .

A) $791 < \mu _ { 1 } - \mu _ { 2 } < 811$
B) $800 < \mu 1 - \mu _ { 2 } < 802$
C) $781 < \mu _ { 1 } - \mu _ { 2 } < 821$
D) $794 < \mu _ { 1 } - \mu _ { 2 } < 808$