Question

Statistics: Can you check my work?! (Metal+Fan)

Answer 1

A= 24.694
B= 24.694-.995(.27686/sqrt10) = 24.606 24.694+.995(.27686/sqrt10)= 24.781

Answer 2

xbar +/ t(s/sqrtn) is the formula i used

Answer 3

how are you getting 0.995 ?

Answer 4

oh man looks like thats an error - it should be .99 right?

Answer 5

considerin the 99% confidence interval

Answer 6

that's not the critical value though

Answer 7

you'd use a table like this

http://3.bp.blogspot.com/_5u1UHojRiJk/TEdJJc6of2I/AAAAAAAAAIE/Ai0MW5VgIhg/s1600/t-table.jpg

to find the t critical value

Answer 8

oh would you be able to help me with that, for the confidence level i look at 99% but then which df do i look at

Answer 9

df = n-1

so df = 10-1 = 9

Answer 10

look in the row that has df = 9

look in the column with the 99% confidence level

Answer 11

that value will be the t critical value

Answer 12

see attached

Answer 13

okay!
So 3.25 is the T
x bar is 24.694
the square root of n is 3.162
and the s is .2768

Answer 14

so what's your confidence interval now

Answer 15

3.25 :)

Answer 16

that's the t critical value

Answer 17

so what is confidence interval

Answer 18

24.694 + 3.25 (.277/3.162) = 24.979
24.694 - 3.25 (.277/3.162) = 24.407

Answer 19

how are you getting 24.407 ?

Answer 20

I'm getting 24.409

Answer 21

You're right i got 24.40929...
must have typed it incorrectly

Answer 22

so your 99% confidence interval of the mean mu is (24.409, 24.979)

Answer 23

Okay, thanks soo much! (Im actually about to post another stats question - if you have any desire at rattling your brain again)