Statistics Technology & Digital Applications 5

Question 1

A statistician uses Python's statsmodels library to fit an OLS regression and inspects the Durbin-Watson statistic. What assumption does this statistic test?

Accepted Answer

Independence of residuals (autocorrelation)

Answer

The Durbin-Watson statistic ranges from 0 to 4, with values near 2 indicating no autocorrelation among residuals.

Question 2

In Tableau, a 'dimension' field versus a 'measure' field differs primarily in that:

Accepted Answer

Dimensions are categorical/qualitative; measures are quantitative and aggregatable

Answer

Tableau classifies categorical fields used to slice data as dimensions, while numeric fields that are aggregated (sum, avg, etc.) are measures.

Question 3

Which Python library's function numpy.random.normal(loc=0, scale=1, size=1000) is used to generate?

Accepted Answer

1000 samples from a standard normal distribution

Answer

numpy.random.normal() generates random samples from a normal (Gaussian) distribution with specified mean (loc) and standard deviation (scale).

Question 4

A researcher uses Excel's VLOOKUP function to merge two datasets. What is a critical limitation of VLOOKUP?

Accepted Answer

It can only search the leftmost column of the table array

Answer

VLOOKUP always searches the first (leftmost) column of the lookup range, making it unable to return values from columns to the left of the lookup key.

Question 5

In SAS, the PROC FREQ procedure is primarily used for:

Accepted Answer

Generating frequency tables and chi-square tests for categorical data

Answer

PROC FREQ produces frequency tables, cross-tabulations, and chi-square statistics for analyzing categorical variables in SAS.

Statistics Practice Test

Statistics Practice Test

Statistics Technology & Digital Applications 5