CBDA Statistical Analysis & Methods 2

Question 1

Which sampling method ensures that every member of the population has an equal chance of being selected?

Accepted Answer

Simple random sampling

Answer

Simple random sampling gives every individual in the population an equal and independent chance of being included.

Question 2

A CBDA analyst wants to compare average customer satisfaction scores across three or more business regions. Which statistical test is MOST appropriate?

Accepted Answer

One-way ANOVA

Answer

One-way ANOVA tests whether mean scores differ significantly across three or more independent groups.

Question 3

What is 'multicollinearity' and why is it a concern in multiple regression analysis for business analysts?

Accepted Answer

When independent variables are highly correlated with each other, inflating coefficient estimates

Answer

Multicollinearity makes it difficult to isolate the individual effect of each predictor, reducing model interpretability.

Question 4

In descriptive statistics, what does the interquartile range (IQR) measure?

Accepted Answer

The spread of the middle 50% of data values

Answer

The IQR is Q3 minus Q1 and captures the spread of the central half of the data, resistant to outlier influence.

Question 5

A business analyst uses stratified random sampling when analyzing customer data. What is the PRIMARY advantage of this approach?

Accepted Answer

It ensures proportional representation of key subgroups in the sample

Answer

Stratified sampling divides the population into subgroups (strata) and samples from each, ensuring all key segments are represented.

CBDA - Certified Business Data Analyst Practice Test

CBDA - Certified Business Data Analyst Practice Test

CBDA Statistical Analysis & Methods 2