Answer:
$4.0
#See solutions for details.
Step-by-step explanation:
#Given our share prices as:16, 17, 16, 16, 18, 18, 21, 22, 19
# I have used [tex]alcula.com[/tex] to plot a box plot and determine the first and third quartile price difference:
[tex]Third \ quartile-First \ Quartile=20-16\\=4[/tex]
Hence the third quartile is greater than the first quartile by $4.0