:1.  The histogram of dividend earnings in 1986 for a sample of
180 persons is given in figure ?.  There are no persons in the
sample having dividend earnings in excess of $1,500.  The block
over the interval from $400 to $800 is missing.  The height of
this missing block is closest to

 a.  20

 b.  10

 c.  15

 d.  60

 e.  5