Question

WILL GIVE MEDAL, FAN, AND TESIMONIAL!

Soda Tak claims that Diet Tak has 40mg of sodium per can. You work for a consumer organization that tests such claims. You take a random sample of 60 cans and find that the mean amount of sodium in the sample is 42.4mg. The population standard deviation in all cans is 5.2mg. You suspect that there is more than 40mg of sodium per can. Find the z-score
1.785
2.582
3.575
5.143

Answer 1

I know that \[z = \chi - \mu / \sigma \]
from my AP Statistics notes

Answer 2

where \[\mu = mean \]

and

\[\sigma = standard deviation \]

Answer 3

@ybarrap @agent0smith @amistre64

Answer 4

@sdfgsdfgs Thank you for looking at my question... For some reason my calculator keeps coming up with error...

Answer 5

sorry my stats is not very good...

Answer 6

that's ok.

Answer 7

but i found the sol'n 4 u anyway :P

it has been asked n answered on OS be4....scroll half way down this post to see the formula plz

http://openstudy.com/study#/updates/5339edfde4b0720dc69b6621

in ur case, there IS a right ans ;)

Answer 8

\[Z = X- E[X] / \sigma (X) / \sqrt{n}\]

Answer 9

is the equation given.... Sorry I was having dinner with my family we are not allowed to have any electronics at the table... House Rule

Answer 10

hehehee strict family dinning rulez huh? :)

its ok but yes, dats the eqn to calculate the Z-score in this case n it works!

Answer 11

Yup. and X is = score

Correct?

Answer 12

What do X an n stand for?

Answer 13

X=experimental mean and n is sample size

Answer 14

ok.

Answer 15

give me a sec to build the equation

Answer 16

\[Z= 40 - E [42.4] /\sigma [40] / \sqrt{5.2}\]

Answer 17

I have no idea if I did this right.... I am really bad with setting up my equations

Answer 18

n is not equal to 5.2....

Answer 19

what are E and \[\sigma \]

Answer 20

AAAAHHHH!!!!
\[\sigma = 5.2\]

Answer 21

n = 60

Answer 22

@sdfgsdfgs

better

Answer 23

is E= 40?

Answer 24

:) all correct!

Answer 25

ok so......

Answer 26

hahahaa cant do this w/o a calculator....u done w dinner yet? ;)

Answer 27

yup.

Answer 28

i'm setting it up and plugging it in now

Answer 29

in ur prob, there IS a right ans...unlike the last time...

Answer 30

\[Z = 40 - 40 (42.4) / (5.2) (40) / \sqrt{60}\]

Answer 31

is that correct?

Answer 32

Z=X−E[X]/σ(X)/√n
is really Z=(X-E)/σ/√n

but ur eqn will work out as the 40 above n below will cancel each other out

Answer 33

ok. so i keep getting either -1644.251219 OR 39.00692735

Answer 34

Z=|(42.4-40)|/(5.2)/√60

Answer 35

41.40692735

Answer 36

@kropot72
Can you see what I am doing wrong?

Answer 37

how about this:
Z=|(42.4-40)|/(5.2/√60)

Answer 38

same answer...

Answer 39

That is the same problem as before

Answer 40

Z=\[\frac{ 42.4-40 }{ \frac{ 5.2 }{ \sqrt{60} } }\]

Answer 41

3.575

Answer 42

so the answer would be C

Thank you very much for your help!!

Answer 43

welcome n u may want to re-trace ur calculation to see where u made a mistake n did not come up w the right ans. good luck! :)