1. ## confidence intervals

this is one of my questions on my homework this week and I'm not sure I'm doing it right. The further I get in this class the more I feel lost.

1. The amounts (in ounces) of juice in eight randomly selected juice bottles are:

15.4 15.7 15.2 15.8 15.8 15.4 15.0 15.6

Assuming the population of amounts in juice bottles is known to be normally distributed, create a 95% confidence interval estimate for , the mean amount of juice in all bottles.

You will be asked to identify x-bar, s, alpha, df, t, E and the confidence interval. (3 points each)

This is what I have come up with so far:
X-bar = 15.488
S = .290
alpha = .05
df = 7
T =
E =
critical value= 1.96
CI = (15.2456, 15.7304)

Is this right so far? I have a partner in my class I'm working on this with and her answers are totally different than mine.

2. Originally Posted by rclements3
this is one of my questions on my homework this week and I'm not sure I'm doing it right. The further I get in this class the more I feel lost.

1. The amounts (in ounces) of juice in eight randomly selected juice bottles are:

15.4 15.7 15.2 15.8 15.8 15.4 15.0 15.6

Assuming the population of amounts in juice bottles is known to be normally distributed, create a 95% confidence interval estimate for , the mean amount of juice in all bottles.

You will be asked to identify x-bar, s, alpha, df, t, E and the confidence interval. (3 points each)

This is what I have come up with so far:
X-bar = 15.488
S = .290
alpha = .05
df = 7
T =
E =
critical value= 1.96
CI = (15.2456, 15.7304)

Is this right so far? I have a partner in my class I'm working on this with and her answers are totally different than mine.
Your critical value is wrong but somehow you got the correct confidence interval ....??
The critical value of T is 2.3646, not 1.96 (that's the critical value for Z. And you realise that Z is not used because the population sd is not known).