The National Institute on Drug Abuse surveyed U.S. high school seniors every two years to determine the percentage who said they had used marijuana one or more times. The following time-series plot presents the results.

a. During what year was marijuana use among high school students the highest?

b. True or false: At one time, more than half of all high school students reported using marijuana.

c. During what periods of time was marijuana use increasing?

d. During what periods of time was marijuana use decreasing?

e. True or false: Marijuana use among high school students in 2012 was lower than it had been since 1992.

Transcribed Image Text:

50 50 40 40 30 30 20 20 Percent 10- 0 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010 2012 2014