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Результат анализа данных в пакете Statgraphics.

One-Variable Analysis - d17

Data variable: d17

11006 values ranging from 1.0 to 81.0

The StatAdvisor

This procedure is designed to summarize a single sample of data. It will calculate various statistics and graphs. Also included in the procedure are confidence intervals and hypothesis tests.

Summary Statistics for d17

Count

11006

Average

1.54207

Median

1.0

Mode

1.0

Variance

2.8936

Standard deviation

1.70106

Coeff. of variation

110.31%

Range

80.0

Skewness

19.0631

Stnd. skewness

816.457

Kurtosis

738.472

Stnd. kurtosis

15814.1

The StatAdvisor

This table shows summary statistics for d17. It includes measures of central tendency, measures of variability, and measures of shape. Of particular interest here are the standardized skewness and standardized kurtosis, which can be used to determine whether the sample comes from a normal distribution. Values of these statistics outside the range of -2 to +2 indicate significant departures from normality, which would tend to invalidate any statistical test regarding the standard deviation. In this case, the standardized skewness value is not within the range expected for data from a normal distribution. The standardized kurtosis value is not within the range expected for data from a normal distribution.

Frequency Tabulation for d17

Lower

Upper

Relative

Cumulative

Cum. Rel.

Class

Limit

Limit

Midpoint

Frequency

Frequency

Frequency

Frequency

at or below

-3.0

0

0.0000

0

0.0000

1

-3.0

-0.560976

-1.78049

0

0.0000

0

0.0000

2

-0.560976

1.87805

0.658537

8081

0.7342

8081

0.7342

3

1.87805

4.31707

3.09756

2575

0.2340

10656

0.9682

4

4.31707

6.7561

5.53659

199

0.0181

10855

0.9863

5

6.7561

9.19512

7.97561

100

0.0091

10955

0.9954

6

9.19512

11.6341

10.4146

21

0.0019

10976

0.9973

7

11.6341

14.0732

12.8537

13

0.0012

10989

0.9985

8

14.0732

16.5122

15.2927

2

0.0002

10991

0.9986

9

16.5122

18.9512

17.7317

4

0.0004

10995

0.9990

10

18.9512

21.3902

20.1707

5

0.0005

11000

0.9995

11

21.3902

23.8293

22.6098

2

0.0002

11002

0.9996

12

23.8293

26.2683

25.0488

2

0.0002

11004

0.9998

13

26.2683

28.7073

27.4878

0

0.0000

11004

0.9998

14

28.7073

31.1463

29.9268

0

0.0000

11004

0.9998

15

31.1463

33.5854

32.3659

0

0.0000

11004

0.9998

16

33.5854

36.0244

34.8049

0

0.0000

11004

0.9998

17

36.0244

38.4634

37.2439

0

0.0000

11004

0.9998

18

38.4634

40.9024

39.6829

0

0.0000

11004

0.9998

19

40.9024

43.3415

42.122

0

0.0000

11004

0.9998

20

43.3415

45.7805

44.561

0

0.0000

11004

0.9998

21

45.7805

48.2195

47.0

0

0.0000

11004

0.9998

22

48.2195

50.6585

49.439

0

0.0000

11004

0.9998

23

50.6585

53.0976

51.878

0

0.0000

11004

0.9998

24

53.0976

55.5366

54.3171

0

0.0000

11004

0.9998

25

55.5366

57.9756

56.7561

0

0.0000

11004

0.9998

26

57.9756

60.4146

59.1951

0

0.0000

11004

0.9998

27

60.4146

62.8537

61.6341

0

0.0000

11004

0.9998

28

62.8537

65.2927

64.0732

0

0.0000

11004

0.9998

29

65.2927

67.7317

66.5122

0

0.0000

11004

0.9998

30

67.7317

70.1707

68.9512

0

0.0000

11004

0.9998

31

70.1707

72.6098

71.3902

0

0.0000

11004

0.9998

32

72.6098

75.0488

73.8293

1

0.0001

11005

0.9999

33

75.0488

77.4878

76.2683

0

0.0000

11005

0.9999

34

77.4878

79.9268

78.7073

0

0.0000

11005

0.9999

35

79.9268

82.3659

81.1463

1

0.0001

11006

1.0000

36

82.3659

84.8049

83.5854

0

0.0000

11006

1.0000

37

84.8049

87.2439

86.0244

0

0.0000

11006

1.0000

38

87.2439

89.6829

88.4634

0

0.0000

11006

1.0000

39

89.6829

92.122

90.9024

0

0.0000

11006

1.0000

40

92.122

94.561

93.3415

0

0.0000

11006

1.0000

41

94.561

97.0

95.7805

0

0.0000

11006

1.0000

above

97.0

0

0.0000

11006

1.0000

Mean = 1.54207 Standard deviation = 1.70106

The StatAdvisor

This option performs a frequency tabulation by dividing the range of d17 into equal width intervals and counting the number of data values in each interval. The frequencies show the number of data values in each interval, while the relative frequencies show the proportions in each interval. You can change the definition of the intervals by pressing the alternate mouse button and selecting Pane Options. You can see the results of the tabulation graphically by selecting Frequency Histogram from the list of Graphical Options.

Percentiles for d17

Percentiles

1.0%

1.0

5.0%

1.0

10.0%

1.0

25.0%

1.0

50.0%

1.0

75.0%

2.0

90.0%

3.0

95.0%

4.0

99.0%

7.0

Confidence Intervals for d17

95.0% confidence interval for mean: 1.54207 +/- 0.0317799 [1.51029, 1.57385]

95.0% confidence interval for standard deviation: [1.67888, 1.72383]

The StatAdvisor

This pane displays 95.0% confidence intervals for the mean and standard deviation of d17. The classical interpretation of these intervals is that, in repeated sampling, these intervals will contain the true mean or standard deviation of the population from which the data come 95.0% of the time. In practical terms, we can state with 95.0% confidence that the true mean d17 is somewhere between 1.51029 and 1.57385, while the true standard deviation is somewhere between 1.67888 and 1.72383.

Both intervals assume that the population from which the sample comes can be represented by a normal distribution. While the confidence interval for the mean is quite robust and not very sensitive to violations of this assumption, the confidence interval for the standard deviation is quite sensitive. If the data do not come from a normal distribution, the interval for the standard deviation may be incorrect. To check whether the data come from a normal distribution, select Summary Statistics from the list of Tabular Options, or choose Normal Probability Plot from the list of Graphical Options.

Hypothesis Tests for d17

Sample mean = 1.54207

Sample median = 1.0

Sample standard deviation = 1.70106

t-test

Null hypothesis: mean = 0

Alternative: not equal

Computed t statistic = 95.1041

P-Value = 0

Reject the null hypothesis for alpha = 0.05.

sign test

Null hypothesis: median = 0

Alternative: not equal

Number of values below hypothesized median: 0

Number of values above hypothesized median: 11006

Large sample test statistic = 104.9 (continuity correction applied)

P-Value = 0

Reject the null hypothesis for alpha = 0.05.

signed rank test

Null hypothesis: median = 0

Alternative: not equal

Average rank of values below hypothesized median: 0

Average rank of values above hypothesized median: 5503.5

Large sample test statistic = (continuity correction applied)

P-Value = 0

Reject the null hypothesis for alpha = 0.05.

chi-square test

Null hypothesis: sigma = 1.0

Alternative: not equal

Computed chi-square statistic = 31844.0

P-Value = 0

Reject the null hypothesis for alpha = 0.05.

The StatAdvisor

This pane displays the results of tests concerning the population from which the sample of d17 comes. The t-test tests the null hypothesis that the mean d17 equals 0.0 versus the alternative hypothesis that the mean d17 is not equal to 0.0. Since the P-value for this test is less than 0.05, we can reject the null hypothesis at the 95.0% confidence level. The sign test tests the null hypothesis that the median d17 equals 0.0 versus the alternative hypothesis that the median d17 is not equal to 0.0. It is based on counting the number of values above and below the hypothesized median. Since the P-value for this test is less than 0.05, we can reject the null hypothesis at the 95.0% confidence level. The signed rank test tests the null hypothesis that the median d17 equals 0.0 versus the alternative hypothesis that the median d17 is not equal to 0.0. It is based on comparing the average ranks of values above and below the hypothesized median. Since the P-value for this test is less than 0.05, we can reject the null hypothesis at the 95.0% confidence level. The sign and signed rank tests are less sensitive to the presence of outliers but are somewhat less powerful than the t-test if the data all come from a single normal distribution.

The chi-square test tests the null hypothesis that the standard deviation of d17 equals 1.0 versus the alternative hypothesis that the standard deviation of d17 is not equal to 1.0. Since the P-value for this test is less than 0.05, we can reject the null hypothesis at the 95.0% confidence level.

Как видно, результаты программы на Python совпадают с результатами из Statgraphics.