How much population falls between median and median plus one standard deviation in a normal distribution ?
0.34
0.68
0.17
0.47
NORMAL DISTRIBUTION

Shape is bilaterally symmetrical
Mean = Median = Mode (coincide)
50% of all values lie above Mean (or Median or Mode)
Mean + 1SD cover 68% values (Mean + 1SD cover 34% values)
Mean + 2SD cover 95% values (Mean + 2SD cover 47.5% values)
Mean + 3SD cover 99% values (Mean + 3SD cover 49.5% values)