After a set of surveys was compiled and analyzed, the mean value was reported as 42 ± 3. Which statement is true for this data?
a) Approximately 95% of the data fall between 39 and 45.
b) Approximately 68% of the data fall between 39 and 45.
c) Approximately 95% of the data fall between 39 and 42.
d) Approximately 68% of the data fall between 42 and 45.
