Calculate cutoff values and analyzing histograms, Advanced Statistics

Assignment Help:

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?


Related Discussions:- Calculate cutoff values and analyzing histograms

Rejection Region (graded), How is the rejection region defined and how is t...

How is the rejection region defined and how is that related to the z-score and the p value? When do you reject or fail to reject the null hypothesis? Why do you think statisticians

Explain negative hyper geometric distribution, Negative hyper geometric dis...

Negative hyper geometric distribution : In sampling without replacement from the population comprising of r elements of one kind and N - r of another, if two elements corresponding

SCATTER DIAGRAM, MEANING ,IMPORTANCE AND RELEAVANCE OF SCATTER DIAGRAM

MEANING ,IMPORTANCE AND RELEAVANCE OF SCATTER DIAGRAM

Quota sample, Quota sample is the sample in which the units are not select...

Quota sample is the sample in which the units are not selected at the random, but in terms of a particular number of units in each of a number of categories; for instance, 10 men

Bivariate boxplot, Bivariate boxplot : A bivariate analogue of boxplot in w...

Bivariate boxplot : A bivariate analogue of boxplot in which the inner area contains 50%of the data, and a 'fence' helps to identify the potential outliers. Robust methods or techn

Density estimation, Procedures for estimating the probability distributions...

Procedures for estimating the probability distributions without supposing any particular functional form. Constructing the histogram is perhaps the easiest example of such type of

Change point problems, Change point problems : Problems with chronologicall...

Change point problems : Problems with chronologically ordered data collected over the period during which there is known to have been a change in the underlying data generation cou

Fractional factorial design, Designs in which the information on main effec...

Designs in which the information on main effects and low-order inter- actions are attained by running only the fraction of the complete factorial experiment and supposing that part

Doubly multivariate data, This term is sometimes used for the data collecte...

This term is sometimes used for the data collected in those longitudinal studies in which more than the single response variable is recorded for each subject on each occasion. For

Queuing theory, 1) Let N1(t) and N2(t) be independent Poisson processes wit...

1) Let N1(t) and N2(t) be independent Poisson processes with rates, ?1 and ?2, respectively. Let N (t) = N1(t) + N2(t). a) What is the distribution of the time till the next epoch

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd