To find the value that is some number of standard deviations above or below the mean, we will add or subtract some multiple of the standard deviation, S, to the sample mean X. The average playing time was given to be 35 minutes with a standard deviation of 2 minutes, so we have X equals (blank) and S
equals (blank), To Find find a value above the mean indicates we will use addition F in finding the value below, the mean indicates, we will use subtraction
F finding values that are away from the mean, includes values that are above and below the main indicating we will use addition and subtraction.