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Statistical Analysis of Calibrated Data I\'m doing a lab report where i\'m asked

ID: 3200908 • Letter: S

Question

Statistical Analysis of Calibrated Data

I'm doing a lab report where i'm asked to find a few of statistics of a set of data. The average and standard deviations are easy, as well as the average deviation, as we are told to just use excel. The issue arises with the last two statistics. I'm unsure about what the question is asking. I know how to find the Q values for the highest and lowest points, but am unsure as to what this is asking me to do. I also don't know how to find the Q-Critical value for my data. Please help! also if you know of a way to find q test values using excel without having to do the more complicated input that would be amazing if you could show me! Thanks!

Actual Measured Mass of mass (g) water (g) volume (mL)c Average (mL) Standard deviation Average deviation Q-test confidence of high value Q-test confidence of low value Correction volume (mLOd 0.530 0.020 -0.017 -0.039 0.029 0.021 0.107 0.001 0.005 -0.028 -0.063 -0.169 -0.102

Explanation / Answer

Please find the data in ascending order with values for mean, stdev and avdev which I got in excel:

Q test is used to reject the outliers

Q = gap/range where gap is the absolute difference between the outlier in question and the closest number to it

Both gao and range can be easily calculated in excel

Q at the lower side is to reject outlier at the lower side = QL

QL = |-.039+.028| / (.53-.039) = .019

Q at the higher side is to reject outlier at the higher side = QH

QH = |.53 -.107| / (.53-.039) = .743

There is Q critical value table which can be used to test whether outliers need to be rejected:

So for 10 data points and 90% confidence interval,

critical value for Q is .412,

Since QH > Critical value of Q, the high value .53 is an outlier

QL < Critical value of Q, the low value -.039 is not an outlier


Sequence Correction volume 1 -0.039 2 -0.028 3 -0.021 4 -0.017 5 0.001 6 0.005 7 0.02 8 0.029 9 0.107 10 0.53 Mean 0.0587 Std Dev 0.170683 Average deviation 0.10392