The average gestation period, or time of pregnancy, of an animal is closely related to its longevity — the length of its lifespan. Data on the average gestation period and longevity (in captivity) of 40 different species of animals have been recorded.

Here is a summary of the variables in our dataset:

- animal: the name of the animal species.
- gestation: the average gestation period of the species, in days.
- longevity: the average longevity of the species, in years.

Though, we will provide the needed output in the question below, we encourage you to try to produce this output on your own.

SPSS Steps:

- Label Variables amd Define Variable Properties
- Create Scatterplot: GRAPHS > CHART BUILDER, create a simple scatterplot relating X = longevity to Y = gestation
- Calculate Correlation: ANALYZE > CORRELATE > BIVARIATE, calculate the correlation between longevity and gestation as illustrated
- Remove Outlier and Save New Data: select the row containing the outlier, right-click on the row number and choose CUT
- Re-create Scatterplot: GRAPHS > CHART BUILDER, create a simple scatterplot relating X = longevity to Y = gestation using the new dataset
- Re-calculate Correlation: ANALYZE > CORRELATE > BIVARIATE, calculate the correlation on the new dataset

SAS Steps:

- Label Variables: Using a DATA step create a new dataset (animals2) where you label the varibles longevity and gestation as Longevity (years) and Gestation (days) using a LABEL statement.
- View Dataset Information in SAS: Use PROC CONTENTS to view the information about the new dataset.
- Create Basic Scatterplot: Use PROC SGPLOT and the SCATTER statement to create a scatterplot of X=longevity by Y=gestation
- Calculate Correlation Coefficient: Use PROC CORR to calculate the correlation coefficient between X=longevity by Y=gestation. In SAS 9.3 you will likely get the scatterplot matrix automatically, in SAS 9.2 you must request this by using ODS GRAPHICS ON before the procedure and ODS GRAPHIC OFF to stop producing this output after the procedure (or whenever you wish to stop producing ODS GRAPHICS).
- Delete Outlier: Using a DATA step create a new dataset (animals3) and use an IF-THEN statement to delete the observation corresponding to the outlier. This outlier is an elephant with average longevity of 40 years and average gestation of 645 days.
- View Dataset Information in SAS: Use PROC CONTENTS to view the information about the new dataset where you have removed the outlier.
- Create Basic Scatterplot: Use PROC SGPLOT and the SCATTER statement to create a scatterplot of X=longevity by Y=gestation on the dataset with the outlier removed.
- Calculate Correlation Coefficient: Use PROC CORR to calculate the correlation coefficient bewteen X=longevity by Y=gestation on the dataset with the outlier removed.

Learn By Doing

Question prompt

Question:

Question

A
Choice 1

B
Choice 2

C
Choice 3

D
Choice D

E
Choice E

F
Choice F

G
Choice G

H
Choice H