These self-assessment problems accompany our in-class discussions on Local measures of precision, and measures in one dimension.
In class we discussed precision vs. accuracy and, in doing so, we looked at four instances: a, b, c, and d. Then I asked you whether b or c was better. And whether b or d was better.
In both cases we answered that “it depends”. Explain why this is. Provide supporting examples for each case.
In your earlier courses you will have looked at a handful of so-called “standard” measures of precision.
a) Provide examples of such measures
b) Explain the meaning of the term “standard”
For random variable that is normally distributed:
a) What confidence level corresponds to ?
b) What confidence level corresponds to ?
c) What confidence level corresponds to ?
d) How many ‘s correspond to a 95% confidence level?
e) How many ‘s correspond to a 50% confidence level?
Sketch each of the above cases and include appropriately shaded areas and labeling of the key values and probabilities
What is the “multiplier”, , in each of the above cases? Describe in words the meaning of this multiplier and why we need it.
Imagine you do a leveling survey and a subsequent adjustment to estimate the heights of three points,
And imagine that your least squares estimate yields the following variance-covariance matrix of the adjusted unknowns in units of :
a) What is the Linear Error Probable (LEP) for each point?
b) What is the standard deviation for each?
c) Assuming a normal distribution, which of the estimated heights would be acceptable if the 3- error limit in height was 2.00 mm?
Imagine that your least squares estimate of the coordinates of 15 points yields a variance-covariance matrix of the adjusted unknowns. A subset of that matrix is given below for just the heights of points 4 and 9 in units of :
a) Provide a measure of uncertainty in height for point 4 at the 95.4% confidence level
b) Provide a measure of uncertainty in height for point 9 at the 95.4% confidence level
c) What is the meaning of the 95.4% confidence level?
d) Provide a measure of the relative uncertainty for the heights of points 4 and 9 at the 95.4% confidence level
e) Is a measure of uncertainty or relative uncertainty more meaningful? Explain.