# Data Analysis Descriptive Statistics Topics: Statistics, Standard deviation, Variance, Arithmetic mean, Regression analysis, Median / Pages: 4 (301 words) / Published: Dec 13th, 2014

Data Analysis
Descriptive Statistics, Estimation, Regression & Correlation
Treatment Effects of a Drug on Cognitive Functioning in Children with Mental Retardation and ADHD

Hossam Elhowary
MATH-1016-15
Dr. Maria DeLucia
December 09, 2014

Introduction
The purpose of this survey was to investigate the cognitive effects of stimulant medication in children with mental retardation and Attention-Deficit/Hyperactivity Disorder. Twenty four children were given various dosage of a drug a placebo and 0.60mg/kg. Variable descriptions are kind of drug taken and the number of correct responses after taking of the drug. They were on each dose one week before testing. This sample obtained from the preschool delay task of Gordon Diagnostic System (Gordon, 1983). However, does higher dosage lead to higher cognitive performance?
Histogram:

Box-and-whisker plot:

Multi plot:

Summary statistics:

Column n Mean
Variance
Std. dev.
Std. err.
Median
Range
Min
Max
Q1
Q3
Placebo
24
39.75
128.02174
11.314669
2.3095972
36
45
26
71
33
47
0.60
24
44.708333
151.7808
12.319935
2.5147962
42.5
48
29
77
35
54

Simple linear regression results:

Dependent Variable: .60 mg/kg
Independent Variable: Placebo
.60 mg/kg = 10.091611 + 0.87086093 Placebo
Sample size: 24
R (correlation coefficient) = 0.79980157
R-sq = 0.63968255
Estimate of error standard deviation: 7.5614248

Parameter estimates:

Parameter
Estimate
Std. Err.
Alternative
DF
T-Stat
P-value
Intercept
10.091611
5.7500723
≠ 0
22
1.7550408
0.0932
Slope
0.87086093
0.13934708
≠ 0
22
6.2495816
<0.0001

Analysis of variance table for regression model:

Source
DF
SS
MS
F-stat
P-value
Model
1
2233.1051
2233.1051
39.057271
<0.0001
Error
22
1257.8532
57.175145

Total
23
3490.9583

Discussion:
I used the histogram; I found out that the histogram skewed to the right, indicating improvement in children performance who took higher dosage of the drug not a placebo. Using the boxplot can find that mean of 0.60mg/kg drug is higher