How does the accuracy of a calculation depend on the number of significant figures in the measurement used to do the calculations?

In general, a calculated answer cannot be more precise than the least precise measurement from which it was calculated

when it is at an intermediate population density

the circled areas are referred to   as sunspots.   the sunspots are cooler than the   surrounding area.

sunspots are temporary phenomena on the photosphere of the sun that appear visibly as dark spots compared to surrounding regions. they correspond to concentrations of magnetic field flux that inhibit convection and result in reduced surface temperature compared to the surrounding photosphere.