Problem 1: Calculate the design factor of sky.  Take a daily sample of sky for at least forty years.  Create a holdout universe of ten percent.  Run bootstrap tests on your remaining observations.  What is the standard deviation of sky?  Why did you need to look again and again?

Problem 2: Sky is slippery.  What can you design to hold onto sky?  A few examples: the weather in Middlemarch; Abstract Expressionism; Black Oil beetle wings.

Problem 3:  Regression to the mean is a common problem when fusing clouds, resulting in a bland and overcast sky.  How will you mitigate this challenge?  Your choice of variables is critical.  Bear in mind analysis is only possible in retrospect.  Show your workings.