Essay title: Spss
Introduction
This paper reports and analyses the findings of a questionnaire about TV viewing. There are eight variables to the questionnaire and these variables are a variety of scales of measurement.
Descriptive statistics provide important information about variables. Mean, median and mode measure central tendency of a variable. Although normal distribution is often assumed, that is not always the case. Graphical methods to test normality allow visualization and comparison of the distribution of a random variable. These methods are both descriptive and theory oriented. This study incorporates graphical methods, both descriptive; Stem-and-leaf plot, box plot, Histogram, and Theory; Q-Q plot.
All statistics, graphs, and cross-tabulations were prepared using the SPSS software. The data was collected on February 8, 2008 and is based on actual responses from respondents that are associated with the author.
TV hours
Descriptive Statistics
Descriptive Statistics (Also, calculate the coefficient of variation)
Statistics
Valid
Missing
Variance
117.895
Frequency
Percent
Valid Percent
Cumulative Percent
Valid
100.0
Total
100.0
100.0
Descriptive Statistics
Minimum
Maximum
Std. Deviation
15.97
10.858
Valid N (listwise)
(2) Histogram (Superimpose the normal curve over the histogram)
(3) Stem- and- Leaf
Hours Stem-and-Leaf Plot
Frequency Stem & Leaf
2.00 0 . 22
14.00 0 . 55555556667888
16.00 1 . 0000000000000004
5.00 1 . 55557
11.00 2 . 00000123444
4.00 2 . 5688
2.00 3 . 03
1.00 3 . 8
4.00 4 . 0223
Stem width: *
Each leaf: 1 case(s)
(4) Box Plot
(5) Test the normality of distribution (One of the methods is QQ plot)
By looking at the descriptive statistics charts, we can see that the average hours of TV watched per week (mean) is 15.97. This is due to the fact the highest frequency of TV hours is between 2 and 20 hours a week. The histogram provides us with a graphic view of the data. We can see that the bars are skewed to the left, and it is evident that most of the observations are to the left of the mean. If a variable is normally distributed, its median and mean are