What percentage of all scores fall below a z score of +1?

A) 16%
B) 34%
C) 50%
D) 84%

In a standard normal distribution, a z-score of +1 is one standard deviation above the mean. Approximately 34% of scores lie between the mean and a z-score of +1, and since about 50% of scores are below the mean, adding these percentages gives us 84% of scores falling below a z-score of +1.