Determining appropriate range from test data

ChaoticLlama · Sep 23, 2012

Hello all.

I am performing chemistry experiments and recording the times of various observed results. What I am doing currently is performing the test several times in order to determine what result is "normal."

My goal is to determine a range as a standard by which all future tests will be compared against. I do not know the correct expected time for these results; this will be set by my experiments.

Say for example we use this test data in seconds:

22
25
26
25
25
25
26
27
24
25

The full range of data is 22 to 27 with the average being 25, But maybe the "acceptable" range should be 25-27.

I would like to know what tools I should use to analyze this data to determine statistically what range of data should be considered normal.

Thank you.

chiro · Sep 23, 2012

Hey ChaoticLlama.

One thing you can do is to use a distribution (i.e. a statistical one based on your sample, or if you make an assumption on the population), and look at the interval corresponding to the a/2 in each tail where 1-a corresponds to the probability that defines your interval.

A lot of people would use a normal distribution and then find the 95% interval for that distribution, but this isn't always right since not everything is always just the "default".

Log in or Sign up

Determining appropriate range from test data

ChaoticLlama

chiro

Hypothesis test on ordinal data (Replies: 11)

The appropriate test statistic? (Replies: 3)

Calculating variance from range (Replies: 2)

Testing to see if my data is uniform (Replies: 2)

Determine if a test procedure is unbiased (Replies: 2)