One of these pairings of histogram with normal quantile plot shows data that have been rounded. The other shows the same data without rounding. The rounding in the example is similar to the rounding...

One of these pairings of histogram with normal quantile plot shows data that have been rounded. The other shows the same data without rounding. The rounding in the example is similar to the rounding in SAT scores.

(a) Which is which? How can you tell?

(b) Why do the histograms appear so similar if the data are different?