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oxshannon
Sep16-11, 05:55 PM
1. The problem statement, all variables and given/known data

The following set of analyses represent concentrations of chloride in blood serum (meq/L): 103,106,107,114. One value appears suspect. Determine if it can be rejected at the 95% confidence level.

2. Relevant equations
Mean

Standard Deviation:
http://standard-deviation.appspot.com/images/standard-deviation-2.png

T-Table (http://www.sjsu.edu/faculty/gerstman/StatPrimer/t-table.pdf)

Degrees of Freedom = n -1 (n in this case being 4)

Confidence Interval:
http://www.measuringusability.com/images/CI.jpg


3. The attempt at a solution

So I found the mean to 107.5, and the standard deviation to be 4.65 (If anyone wants to see how I did this, just let me know).

Then using the table, I found that t95 = 3.182 (using that there are 3 degrees of freedom)

Using the confidence interval formula, I calculated the answer to be 107.5 +/- 7.40.

I'm stuck from here and in fact have no idea if I even started this problem properly. PLEASE HELP :(

oxshannon
Sep17-11, 09:04 AM
Anyone? :( I'm super desperate

oxshannon
Sep17-11, 01:58 PM
Actually -- would it be possible to simply use Grubb's test?