Statistics

Running head: STATISTICS 1
Statistics
Student Name
Professor’s Name
University Name
Date

STATISTICS 2
Part 1: Brain Size
Part A: Excel Task
a. We need to use excel to compute the five-number summary using the
head size column.
Answer
The five-number summary include the minimum, 1st quartile, median, 3rd quartile,
and maximum (Hinton, 2014). The summary as obtained in excel for the head size
column is as shown below:
b. The interquartile range and lower/ upper limits for the outliers obtained
in excel are as shown in the figure below.
c. The maximum value is an outlier since it lies beyond the upper limit of
the outlier (Evans & Basu, 2013).
d. The scatter plot created to show the relationship between the head size and the brain
weight inclusive of the regression equation and the r-squared value is as shown below:

STATISTICS 3
e. The Residual vs. fitted plot created using the excel regression tool is as shown below:
Part B: Analysis of Results
1. The type of relationship that exist between head size and brain weight is an averagely
strong positive relationship (Freund, 2014). This is because the multiple r value is
positive and approaching 1. Moreover, the slope of the regression equation is positive.
2. The outliers of the dataset are reasonable in the sense that they are very few hence and
very close to the upper limit and hence has no huge impact on the result obtained.
Omitting the outlier is not necessarily important since it has very little impact on the
obtained result.