Question

Mean=2.7
S=1.7

What's the percentile rank o each?

Order   Score   Z score
1   1   1
2   1   1
3   2   -0.41
4   2   -0.41
5   2   -0.41
6   2   -0.41
7   3   0.17
8   3   0.17
9   5   1.35
10   6   1.94
What percent falls between the lowest and highest scores in your table

Answer 1

Note: Z = (X - Mean)/S

For score 1, the z score is (1 - 2.7)/1.7 = -1

The probability corresponding to an z score can be obtained from standard normal distribution table (z table). Multiply it with 100 to get the percentile rank.

Order	Score	z score	Percentile rank
1	1	-1	15.87
2	1	-1	15.87
3	2	-0.41	34.09
4	2	-0.41	34.09
5	2	-0.41	34.09
6	2	-0.41	34.09
7	3	0.18	57.14
8	3	0.18	57.14
9	5	1.35	91.15
10	6	1.94	97.38

Percentahe of data between lowest and highest scores = 97.38 - 15.87

= 81.51%