Research Methods, Final Project?
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Unit IV: Data Analysis
Data Analysis: Descriptive Statistics and Assumption Testing
Correlation: Descriptive Statistics and Assumption Testing
Frequency Distribution Table
|
Sick days |
Frequency |
|
2 |
1 |
|
3 |
1 |
|
4 |
5 |
|
5 |
13 |
|
6 |
18 |
|
7 |
24 |
|
8 |
18 |
|
9 |
12 |
|
10 | |
|
11 |
2 |
|
More |
2 |
Histogram
Descriptive Statistics Table
|
Mean Annual Sick days per employee |
|
|
|
|
|
Mean |
7.126213592 |
|
Standard Error |
0.186483898 |
|
Median |
7 |
|
Mode |
7 |
|
Standard Deviation |
1.892604864 |
|
Sample Variance |
3.58195317 |
|
Kurtosis |
0.124922603 |
|
Skewness |
0.142249784 |
|
Range |
10 |
|
Minimum |
2 |
|
Maximum |
12 |
|
Sum |
734 |
|
Count |
103 |
Measurement Scale
The measurement scale used in the above data is ratio scale because the exact values between the data can be determined.
Measure of Central Tendency
The mean, median and mode of the data are identical at 7 implying that the data is perfectly identical.
Skewness and Kurtosis
The skewness of mean annual sick days per employee is 0.142 and is within the range of 0.5 and 1 implying that the data is moderately skewed. On the other hand the kurtosis of the data is 0.1249 and falls within the acceptable region because the curve is not highly picked.
Evaluation
The histogram of the above data is normally distributed and the frequency does not show outliers. The mean, median and more are closely aligned implying normalcy. The skewness and the kurtosis are within the acceptable range of -2 and + 2. The results of the descriptive statistics show that the assumption of the parametric statistics has been met.
Simple Regression: Descriptive Statistics and Assumption Testing
Frequency Distribution Table
.
|
Lost Time in Hours |
Frequency |
|
10 |
1 |
|
35 |
1 |
|
60 |
9 |
|
85 |
9 |
|
110 |
17 |
|
135 |
18 |
|
160 |
24 |
|
185 |
27 |
|
210 |
37 |
|
235 |
24 |
|
260 |
21 |
|
285 |
15 |
|
310 |
12 |
|
335 |
4 |
|
More |
4 |
Histogram
Descriptive Statistics Table
|
Lost Time in Hours |
|
|
|
|
|
Mean |
188.0044843 |
|
Standard Error |
4.803089447 |
|
Median |
190 |
|
Mode |
190 |
|
Standard Deviation |
71.72542099 |
|
Sample Variance |
5144.536016 |
|
Kurtosis |
-0.501223533 |
|
Skewness |
-0.081984874 |
|
Range |
350 |
|
Minimum |
10 |
|
Maximum |
360 |
|
Sum |
41925 |
|
Count |
223 |
Measurement Scale
The lost time per member of contract is ratio data because the data can be classified and ordered.
Measure of Central Tendency
The mean, median and the mode of the data is 188.00, 190 and 190 respectively. These values are closely aligned implying the data is normally distributed.
Skewness and Kurtosis
The skewness and kurtosis of the data is within the acceptable region because the values lies between -2 and + 2.
Evaluation
From the descriptive statistics table the three measures of central tendency are close to each other indicating the normalcy of the data. On the other hand the skewness and the kurtosis of the data is within the acceptable range of -2 and + 2 which shows that the data is normally distributed. These results confirm that the assumption of the parametric statistics has been met.
Multiple Regression: Descriptive Statistics and Assumption Testing
Frequency Distribution Table
|
Decibel |
Frequency |
|
103.38 |
1 |
|
104.37 |
2 |
|
105.36 |
1 |
|
106.35 |
3 |
|
107.34 |
6 |
|
108.33 |
6 |
|
109.32 |
9 |
|
110.31 |
12 |
|
111.30 |
18 |
|
112.29 |
17 |
|
113.28 |
26 |
|
114.27 |
22 |
|
115.26 |
27 |
|
116.25 |
47 |
|
117.24 |
36 |
|
118.22 |
44 |
|
119.21 |
47 |
|
120.20 |
53 |
|
121.19 |
61 |
|
122.18 |
60 |
|
123.17 |
62 |
|
124.16 |
74 |
|
125.15 |
70 |
|
126.14 |
81 |
|
127.13 |
93 |
|
128.12 |
73 |
|
129.11 |
105 |
|
130.10 |
80 |
|
131.09 |
88 |
|
132.08 |
67 |
|
133.07 |
50 |
|
134.06 |
56 |
|
135.05 |
35 |
|
136.04 |
30 |
|
137.03 |
19 |
|
138.02 |
7 |
|
139.01 |
8 |
|
140.00 |
5 |
|
More |
2 |
Histogram
Descriptive Statistics Table
|
Decibel |
|
|
|
|
|
Mean |
124.83594 |
|
Standard Error |
0.1779447 |
|
Median |
125.721 |
|
Mode |
127.315 |
|
Standard Deviation |
6.8986566 |
|
Sample Variance |
47.591463 |
|
Kurtosis |
-0.3141873 |
|
Skewness |
-0.4189522 |
|
Range |
37.607 |
|
Minimum |
103.38 |
|
Maximum |
140.987 |
|
Sum |
187628.42 |
|
Count |
1503 |
Measurement Scale
The measurement scale of decibel is ratio data because the data has meaningful distance between the data values.
Measure of Central Tendency
The mean, median and mode of the data are closely aligned implying normalcy. The results are shown in the table of descriptive statistics above.
Skewness and Kurtosis
The skewness and the kurtosis of the data is within the acceptable region of -2 and + 2. This indicates that the data is normally distributed.
Evaluation
The skewness and the kurtosis of the data show normalcy since the values lies between -2 and +2. Additionally the mean, median and the mode are closely aligned which is a sign of normal distribution. The normalcy of the data indicates that the assumption of parametric statistics has been met.
Independent Samples t Test: Descriptive Statistics and Assumption Testing
Frequency Distribution Table
|
Group A Prior to Training |
Frequency |
|
50 |
4 |
|
55.86 |
5 |
|
61.71 |
7 |
|
67.57 |
8 |
|
73.43 |
14 |
|
79.29 |
10 |
|
85.14 |
8 |
|
More |
6 |
|
Group B prior to Training |
Frequency |
|
75 |
2 |
|
78.14 |
5 |
|
81.29 |
10 |
|
84.43 |
12 |
|
87.57 |
14 |
|
90.71 |
11 |
|
93.86 |
5 |
|
More |
3 |
Histogram
Descriptive Statistics Table
|
Group A prior to Training |
|
|
|
|
|
Mean |
69.790323 |
|
Standard Error |
1.4027881 |
|
Median |
70 |
|
Mode |
80 |
|
Standard Deviation |
11.045564 |
|
Sample Variance |
122.00449 |
|
Kurtosis |
-0.776676 |
|
Skewness |
-0.0867981 |
|
Range |
41 |
|
Minimum |
50 |
|
Maximum |
91 |
|
Sum |
4327 |
|
Count |
62 |
|
Group B prior to Training |
|
|
|
|
|
Mean |
84.7741935 |
|
Standard Error |
0.65947889 |
|
Median |
85 |
|
Mode |
85 |
|
Standard Deviation |
5.19274195 |
|
Sample Variance |
26.964569 |
|
Kurtosis |
-0.3525379 |
|
Skewness |
0.14408453 |
|
Range |
22 |
|
Minimum |
75 |
|
Maximum |
97 |
|
Sum |
5256 |
|
Count |
62 |
Measurement Scale
The measurement scale used is ratio because the data can be classified and ordered.
Measure of Central Tendency
The mean, median and mode of group A before training are 69.79, 70 and 80. Since the range of the measure of central tendency is small it indicates that the data is normally distributed. On the other hand, mean median and mode of group B before training is 84.79, 85 and 85. This results shows that there is normality.
Skewness and Kurtosis
Skewness and kurtosis are important statistical tools of measurement that are used determine the distribution of data or the shape of the distribution curve. The skewness and kurtosis of the data for group A is -0.776676 and -0.0867981 respectively. According to George and Mallery, (2018), a normally distributed data will have skewness and kurtosis of -2 and +2. As such the data set is normally distributed because if falls within the acceptable range.
Evaluation
From the descriptive statistics table, the central measure of tendency are closely aligned indicate the normality of the data set. Additionally, the skewness and kurtosis are within the range of -2 and + 2 showing that the data is normally distributed. These results confirms the assumptions of the parametric test
Dependent Samples (Paired-Samples) t Test: Descriptive Statistics and Assumption Testing
Frequency Distribution Table
|
Pre-Exposureµg/DL |
Frequency |
|
6 |
1 |
|
13.14 |
3 |
|
20.29 |
5 |
|
27.43 |
6 |
|
34.57 |
8 |
|
41.71 |
13 |
|
48.86 |
9 |
|
More |
4 |
|
Post-Exposureµg/DL |
Frequency |
|
6 |
1 |
|
13.14 |
3 |
|
20.29 |
5 |
|
27.43 |
6 |
|
34.57 |
8 |
|
41.71 |
11 |
|
48.86 |
11 |
|
More |
4 |
Histogram
Descriptive Statistics Table
|
Pre-Exposure µg/dL |
|
|
|
|
|
Mean |
32.8571429 |
|
Standard Error |
1.75230655 |
|
Median |
35 |
|
Mode |
36 |
|
Standard Deviation |
12.2661458 |
|
Sample Variance |
150.458333 |
|
Kurtosis |
-0.5760371 |
|
Skewness |
-0.4251097 |
|
Range |
50 |
|
Minimum |
6 |
|
Maximum |
56 |
|
Sum |
1610 |
|
Count |
49 |
|
Post-Exposure µg/DL |
|
|
|
|
|
Mean |
33.28571429 |
|
Standard Error |
1.781423416 |
|
Median |
36 |
|
Mode |
38 |
|
Standard Deviation |
12.46996391 |
|
Sample Variance |
155.5 |
|
Kurtosis |
-0.654212507 |
|
Skewness |
-0.483629097 |
|
Range |
50 |
|
Minimum |
6 |
|
Maximum |
56 |
|
Sum |
1631 |
|
Count |
49 |
Measurement Scale
The ratio data has been used because the Return on investment per number of contracts can be classified and ordered.
Measure of Central Tendency
The mean, median and mode of the data are 33.29,36 and 38. The three values are close meaning that the data is normally distributed and there is no skewness.
Skewness and Kurtosis
The skewness and kurtosis of both pre and post exposure data are within the acceptable region because the values fall with the range of -2 and +2 for the skewness and -7 to +7 for the kurtosis.
Evaluation
The data presented in the descriptive statistics indicates normally of the data because, skewness and kurtosis fall within the acceptable range of -2 and +2. Additionally, the measure of central tendency are closely aligned which is a sign of normal data. Therefore the assumptions of the parametric statistics have been met.
ANOVA: Descriptive Statistics and Assumption Testing
Frequency Distribution Table
|
A=Air |
Frequency |
|
3 |
1 |
|
5.75 |
3 |
|
8.5 |
4 |
|
11.25 |
8 |
|
More |
4 |
|
B=Soil |
Frequency |
|
6 |
1 |
|
7.75 |
2 |
|
9.5 |
10 |
|
11.25 |
5 |
|
More |
2 |
|
C=Water |
Frequency |
|
3 |
1 |
|
5.25 |
5 |
|
7.5 |
8 |
|
9.75 |
2 |
|
More |
4 |
|
D=Training |
Frequency |
|
3 |
1 |
|
4.25 |
3 |
|
5.5 |
7 |
|
6.75 |
6 |
|
More |
3 |
Histogram
Descriptive Statistics Table
|
|
A=Air |
B=Soil |
C=Water |
D=Training |
|
|
|
|
|
|
|
Mean |
8.9 |
9.1 |
7 |
5.4 |
|
Standard Error |
0.6840 |
0.3900 |
0.5758 |
0.2656 |
|
Median |
9 |
9 |
6 |
5 |
|
Mode |
11 |
8 |
6 |
5 |
|
Standard Deviation |
3.0591 |
1.7442 |
2.5752 |
1.1877 |
|
Sample Variance |
9.3579 |
3.0421 |
6.6316 |
1.4105 |
|
Kurtosis |
-0.6283 |
0.1192 |
-0.2375 |
0.2537 |
|
Skewness |
-0.3608 |
0.4920 |
0.7602 |
0.1592 |
|
Range |
11 |
7 |
9 |
5 |
|
Minimum |
3 |
6 |
3 |
3 |
|
Maximum |
14 |
13 |
12 |
8 |
|
Sum |
178 |
182 |
140 |
108 |
|
Count |
20 |
20 |
20 |
20 |
Measurement Scale
The measurement scale used in the above case if ratio because the data can be classified and ordered.
Measure of Central Tendency
The mean, median and mode of Air are 8.9, 9 and 11. Soil has a mean, median and mode of 9.1, 9 and 8 while water has 7, 6 and 6. On the other hand, training is 5.4, 5 and 5. These values are close to each other implying that the data is normally distributed.
Skewness and Kurtosis
The skewness and kurtosis for all the data set, for Air, soil, water and training is illustrated in the above descriptive statistic and is between -2 and +2, implying that the data is moderately distributed and the distribution curve is not peaked. This confirms that the data falls within the acceptable region.
Evaluation
The mean, median and mode of the data are closely aligned showing the normalcy of the data. Similarly the skewness and kurtosis are within the acceptable range of -2 and +2 indicating that the data is normally distributed.
References
Creswell, J. W., & Creswell, J. D. (2018). Research design: Qualitative, quantitative, and mixed methods approaches (5th ed.). SAGE.
George, D., & Mallery, P. (2018). Descriptive statistics. In IBM SPSS Statistics 25 Step by Step (pp. 126-134). Routledge.
Histogram
Frequency 103.38 104.37 105.36 106.35 107.34 108.33 109.32 110.31 111.30 112.29 113.28 114.27 115.26 116.25 117.24 118.22 119.21 120.20 121.19 122.18 123.17 124.16 125.15 126.14 127.13 128.12 129.11 130.10 131.09 132.08 133.07 134.06 135.05 136.04 137.03 138.02 139.01 140.00 More 1 2 1 3 6 6 9 12 18 17 26 22 27 47 36 44 47 53 61 60 62 74 70 81 93 73 105 80 88 67 50 56 35 30 19 7 8 5 2Decibel
Frequency
Histogram
Frequency 50 55.86 61.71 67.57 73.43 79.29 85.14 More 4 5 7 8 14 10 8 6Group A prior to Training
Frequency
Histogram
Frequency 75 78.14 81.29 84.43 87.57 90.71 93.86 More 2 5 10 12 14 11 5 3Group B prior to Training
Frequency
Histogram
Frequency 6 13.14 20.29 27.43 34.57 41.71 48.86 More 1 3 5 6 8 13 9 4Pre-Exposure µg/dL
Frequency
Histogram
Frequency 6 13.14 20.29 27.43 34.57 41.71 48.86 More 1 3 5 6 8 11 11 4Post-Exposure µg/dL
Frequency
Histogram
Frequency 3 5.75 8.5 11.25 More 1 3 4 8 4A=Air
Frequency
Histogram
Frequency 6 7.75 9.5 11.25 More 1 2 10 5 2B=Soil
Frequency
Histogram
Frequency 3 5.25 7.5 9.75 More 1 5 8 2 4C=Water
Frequency
Histogram
Frequency 3 4.25 5.5 6.75 More 1 3 7 6 3D=Training
Frequency
Histogram
Frequency 2 3 4 5 6 7 8 9 10 11 More 1 1 5 13 18 24 18 12 7 2 2Mean Annual Sick days per Employee
Frequency
Histogram
Frequency 10 35 60 85 110 135 160 185 210 235 260 285 310 335 More 1 1 9 9 17 18 24 27 37 24 21 15 12 4 4Lost Time in Hours
Frequency