Z score tables with percentage of people above a number

Question

The results of a certain medical test are normally distributed with a mean of

130

and a standard deviation of

14.

​(A reading above

118

is considered​ unhealthy). Use the given table to find the percentage of people with readings above

103.

​z-score	​-3.0	​-2.9	​-2.8	​-2.7	​-2.6	​-2.5	​-2.4	​-2.3	​-2.2	​-2.1
Percentile	0.13	0.19	0.26	0.35	0.47	0.62	0.82	1.07	1.39	1.79
​z-score	​-2.0	​-1.9	​-1.8	​-1.7	​-1.6	​-1.5	​-1.4	​-1.3	​-1.2	​-1.1
Percentile	2.28	2.87	3.59	4.46	5.48	6.68	8.08	9.68	11.51	13.57
​z-score	​-1.0	​-0.9	​-0.8	​-0.7	​-0.6	​-0.5	​-0.4	​-0.3	​-0.2	​-0.1
Percentile	15.87	18.41	21.19	24.20	27.43	30.85	34.46	38.21	42.07	46.02

Question content area bottom

Part 1

The percentage of people with readings above

103 is enter your response here​%.

Answer 1

z= (103-130)/14= -27/14= about -2

by the empirical rule 2.5% is less than 2 standard deviatiions below z=-2

and 97.5% above about 103

but use the table to get a more precise percentage and z tables

z tables give .9731 = 97.31% above 103

but that's not considering the table you posted. yet you should get in the same general range

your table has an entry of 2.28 percentile corresponding to -2.0 which is as close to z=27/14 as it gets on your table, so 1-2.28= 97.72% is above 130. That's probably the answer you want