The reaction times of all people in a psychology experiment were normally distributed with a mean of 2 seconds and a standard deviation of 0.5 seconds. (Click here for Z-table.)
a) Make a sketch of the distribution showing the reaction times at 1, 2, and 3 standard deviations from the mean. Also show the percents of the times within 1, 2, and 3 standard deviations of the mean.
b) Find the percent of scores that are:
Less than 0.5 seconds
Greater than 3 seconds
Between 1.5 seconds and 2.5 seconds
c) Find the reaction time at the 20th percentile.