HOW MANY STUDENTS SCORED WITHIN ONE STANDARD DEVIATION OF THE MEAN? PLEASE SHOW WORKING OUT

Question

MEAN : 6.3

MODE:6

MEDIAN:6

STUDENTS SCORES: 4,5,5,6,6,6,7,7,8,9

STANDARD DEVIATION: 1.49

Answer 1

The mean is 6.3 and the standard deviation is 1.49.  Scores within one standard deviation of the mean are between 6.3-1.49 = 4.81 and 6.3+1.49 = 7.79.  How many of the students scored between those two values?

Answer 2

Mean + 1 std dev = 6.3 + 1.49 = 7.79

 

Mean - 1 std dev = 6.3 - 1.49 = 4.81

 

The scores of interest are in the interval (4.81, 7.79)

 

How many students scored in that range????  

 

Hint: It rhymes with heaven