Number of Adults Contracting Colds Cold No cold Total
Vitamin C 21
129
150
Sugar pill 33
150
Total
54
246
300
117
The table shows the results of a research study that
investigated the therapeutic value of vitamin C in
preventing colds. A random sample of 300 adults
received either a vitamin C pill or a sugar pill each
day during a 2-week period, and the adults reported
whether they contracted a cold during that time
period. What proportion of adults who received a
sugar pill reported contracting a cold?
9/50