The results of a certain medical test are normally distributed with a mean of 120 and a standard deviation of 20. Convert the given resul

into 2-scores, and then use the accompanying table of z-scores and percentiles to find the percentage of people with readings between

18

Use the accompanying table of z-scores and percentiles to find the percentage of data items in a normal distribution that lie between

2=0.3 and 2=3.0.

¹Click the icon to view the table of z-scores and percentiles.

The percentage of data items in a normal distribution that lie between z=0.3 and z=3.0 is

(Round to two decimal places as needed.)

1:2-Scores and Percentiles

2-Score

-4.0

-3.5

-3.0

-2.9

-2.8

-2.7

-2.6

-2.5

-2.4

-2.3

-2.2

-2.1

-2.0

-1.9

-1.8

-1.7

-1.6

z-Scores and Percentiles

Score Percentile

-1.0

15.87

-0.95

17.11

-0.90

-0.85

Percentile

0.003

0.02

0.13

0.19

0.26

0.35

0.47

0.62

0.82

1.07

1.39

1.79

2.28

2.87

3.59

4.46

5.48

-1.5

6.68

-1.4

8.08

-1.3 9.68

-1.2

11.51

-1.1

13.57

18.41

19.77

21.19

22.66

-0.80

-0.75

-0.70

24.20

-0.65 25.78

-0.60 27.43

-0.55

29.12

-0.50

30.85

-0.45 32.64

34.46

-0.40

-0.35 36.32

-0.30 38.21

-0.25

40.13

-0.20

42.07

-0.15

44.04

-0.10 46.02

-0.05

48.01

0.0

50.00

z-Score

0.0

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

0.45

0.50

0.55

0.60

0.65

0.70

0.75

0.80

0.85

0.90

0.95

1.0

Percentilez-Score

50.00

51.99

53.98

55.96

57.93

59.87

61.79

63.68

65.54

67.36

69.15

70.88

72.57

74.22

75.80

77.34

78.81

80.23

81.59

82.89

84.13

1.1

12

1.3

14

1.5

1.6

17

18

1.9

2.0

2.1

2.2

2.3

2.4

2.5

2.6

2.7

2.8

2.9

3.0

3.5

4.0

%.

Percentile

86.43

88.49

90.32

91.92

93.32

94.52

95.54

96.41

97.13

97.72

98.21

98.61

98.93

99.18

99.38

99.53

99.65

99.74

99.81

99.87

99.98

99.997