Segment 22. Uncertainty of Derived Parameters

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Watch this segment

(Don't worry, what you see statically below is not the beginning of the segment. Press the play button to start at the beginning.)

The direct YouTube link is http://youtu.be/ZoD3_rov--w

Links to the slides: PDF file or PowerPoint file

Problems

To Compute

1. In lecture slide 3, suppose (for some perverse reason) we were interested in a quantity Failed to parse (unknown error): f = b_3/b_5 instead of Failed to parse (unknown error): f = b_3b_5 . Calculate a numerical estimate of this new Failed to parse (unknown error): f and its standard error.

2. Same set up, but plot a histogram of the distribution of Failed to parse (unknown error): f by sampling from its posterior distribution (using Python, MATLAB, or any other platform).

To Think About

1. Lecture slide 2 asserts that a function of normally distributed RVs is not, in general, normal. Consider the product of two independent normals. Is it normal? No! But isn't the product of two normal distribution functions (Gaussians) itself Gaussian? So, what is going on?

2. Can you invent a function of a single normal N(0,1) random variable whose distribution has two separate peaks (maxima)? How about three? How about ten?