Question

Can anyone help with this?

Answer 1

did you see confidence intervals?
There's a formula saying
\[C.I.=(\mu_1-\mu_2)\pm c\sqrt{\frac{\sigma_1^2+\sigma_2^2}{n}}\]

Answer 2

UGH i suck at those! :( can't they even make this easy?!

Answer 3

=\ that's the reality of confidence intervals lol

Answer 4

ok how do i do this?

Answer 5

\[C.I.=(5.96-4.12)\pm (1.645)\sqrt{\frac{2.49^2+1.85^2}{40}}\]

Answer 6

1.645 is a critical value you find from a standard normal table. You actually look at 0.9500 in the table and find out it has a critical value of 1.645 . But a confidence interval has 2 tails, so that's why you look at the 0.9500 level, since the other 0.05 tail on the left is taken off, resulting in a 90% C.I. value

Answer 7

I got 5.96 &-2.28

Answer 8

Is that right?

Answer 9

i got 2.65 and 1.036

Answer 10

U positive?

Answer 11

um lemme retry i might have mistyped it

Answer 12

http://www.wolframalpha.com/input/?i=%285.96-4.12%29%2B%281.645%29sqrt%28%282.49%5E2%2B1.85%5E2%29%2F40%29

Answer 13

http://www.wolframalpha.com/input/?i=%285.96-4.12%29-%281.645%29sqrt%28%282.49%5E2%2B1.85%5E2%29%2F40%29

Answer 14

2.65 and 1.033

Answer 15

so you write the range is 1.033 hours to 2.65 hours

Answer 16

Yah i did it again using Mathway and got the same as u. i was solving it by hand before so i was getting the wrong answer.

Answer 17

So i put 1.033 in the first box and 2.65 in the 2nd?

Answer 18

yes, although they say round to 2 decimals, so the first box is 1.03

Answer 19

ok
how about the last part?

Answer 20

D .. you conclude there is a significant difference because zero 0 is not in the interval (1.03, 2.65)

Answer 21

ok
Thanks again for the help! :D

Answer 22

np =]

Answer 23

now i just got to check over a few then i can send my homework in!

Answer 24

ok
maybe ask your teacher what kind of "technology" they expect you to use for these problems since I think using R is a bit overboard

Answer 25

well this is my finals homework so i don't need to worry about that as long as i pass this homework. But if u have time can u check and see if i got some questions right? I think i did but i have to be sure or i have to take this class again and i REALLY don't want to do that.

Answer 26

ok

Answer 27

i can try