For the data in table 2.1, dealing with changes in cholesterol levels, suppose a histogram is to be created with bins defined as follows: −40 −30 −20 −10 0 10 20 30 40.

That is, the first bin has boundaries −40 and −30, the next bin contains all values greater than −30 but less than or equal to −20, and so on. Determine the frequencies for each bin and construct a histogram.