Calculate cutoff values and analyzing histograms, Advanced Statistics

1. You are interested in investigating if being above or below the median income (medloinc) impacts ACT means (act94) for schools. Complete the necessary steps to examine univariate grouped data in order to respond to the questions below. Although deletions and/or transformations may be implied from your examination, all steps will examine original variables.

a. How many subjects have missing values for medlonic and act94?

b. Is there a severe split in frequencies between groups?

According to the descriptive analysis, no severe split is detected. This is also reflected in the skewness number which is lower than .5.

c. What are the cutoff values for outliers in each group?

d. Which outlying cases should be deleted for each group?

Average ACT score 1994 Stem-and-Leaf Plot for

medloinc= below the median for low inc % 1993

 Frequency Stem & Leaf

 7.00 14 . 1223789

 9.00 15 . 234478888

 5.00 16 . 12788

 4.00 17 . 1378

 2.00 18 . 09

 1.00 19 . 6

 3.00 20 . 069

 1.00 Extremes (>=22.5)

 Stem width: 1.0

 Each leaf: 1 case(s)

e. Analyzing histograms, normal Q-Q plots, and tests of normality, what is your conclusion regarding normality? If a transformation is necessary, which one would you use?

Tests of Normality

 

above or below median loinc

Kolmogorov-Smirnova

Shapiro-Wilk

 

Statistic

df

Sig.

Statistic

df

Sig.

average ACT score 1994

below the median for low inc % 1993

.162

32

.032

.903

32

.007

above the median for low inc % 1993

.166

32

.025

.921

32

.023

 

According to the information and the test of normality, it appears that this is a normal distribution.  Therefore, for the transformation, we would select 'Square Root."

 

 

f. Do the results from Levene's Test of Equal Variances indicate homogeneity of variance? Explain.

In running the test, there were no significant differences between the categories. Therefore; we can assume that this indicates homogeneity of variance.

2. Examination of the variable of scienc93 indicates a substantial to serve positively skewed distribution. Transform this variable using the most two appropriate methods. After examining the distribution for these transformed variables, which produced the best alteration?

Posted Date: 3/11/2013 3:28:24 AM | Location : United States







Related Discussions:- Calculate cutoff values and analyzing histograms, Assignment Help, Ask Question on Calculate cutoff values and analyzing histograms, Get Answer, Expert's Help, Calculate cutoff values and analyzing histograms Discussions

Write discussion on Calculate cutoff values and analyzing histograms
Your posts are moderated
Related Questions
The contingency tables in which the row and column both the categories follow a natural order. An instance for this might be, drug toxicity ranging from mild to severe, against the

There are two periods. You observe that Jack consumes 100 apples in period t = 0, and 120 apples in period t = 1. That is, (c 0 ; c 1 ) = (100; 120) Suppose Jack has the util

Likelihood is the probability of a set of observations provided the value of some parameter or the set of parameters. For instance, the likelihood of the random sample of n observ

Item-total correlation is an  extensively used method for checking the homogeneity of the scale made up of number of items. It is simply the Pearson's product moment correlation c

Balanced incomplete block design : A design in which all the treatments are not used in all blocks. Such designs have the below stated properties: * each block comprises the

Ordination is the procedure of reducing the dimensionality (that is the number of variables) of multivariate data by deriving the small number of new variables which contain much

Randomized consent design is the design at first introduced to overcome some of the perceived ethical problems facing clinicians entering patients in the clinical trials including

Chernoff's faces : A method or technique for representing the multivariate data graphically. Each observation is represented by the computer-created face, the features of which are

Auto correlation : The correlation of the internal observations in the time series, generally expressed as a function of the time lag between the observations. It is also used for

Prospective study : The studies in which individuals are followed-up over the period of time. A general example of this type of investigation is where the samples of individuals ar