The android app fits lognormals, and 90% rather than 95% confidence intervals. I think they are a more parsimonious distribution for doing these kinds of estimates. One hint might be that, per the central limit theorem, sums of independent variables will tend to normals, which means that products will tend to be lognormals, and for the decompositions quick estimates are most useful, multiplications are more common
The android app fits lognormals, and 90% rather than 95% confidence intervals. I think they are a more parsimonious distribution for doing these kinds of estimates. One hint might be that, per the central limit theorem, sums of independent variables will tend to normals, which means that products will tend to be lognormals, and for the decompositions quick estimates are most useful, multiplications are more common