A data scientist wants to estimate the average height of all employees in a large multinational company. They collect a sample by selecting every 10th name from an alphabetical list of employees. Which potential bias is most likely to affect this estimate?

Non-response bias because some employees may not participate

Measurement error because height is self-reported

No bias because the sample is random

Selection bias due to the systematic sampling frame

What happens to the width of a confidence interval for a population mean when the sample size increases, assuming the confidence level remains the same?

The interval width stays the same.

The interval width becomes unpredictable.

A data scientist at a retail company runs an A/B test to compare two website layouts. The p-value for the conversion rate difference is 0.04, and the 95% confidence interval for the difference is [0.001, 0.02]. The business team wants to launch the new layout. Which additional consideration is most important before deciding to launch?

Ensure the confidence interval does not include zero, which proves the effect is large.

Re-run the test with a larger sample size to confirm the p-value is stable.

Verify that the p-value is below 0.05, which confirms the new layout is better.

Check the effect size to see if the 0.02 absolute improvement is practically meaningful for the business.

What is the primary purpose of inferential statistics?

To visualize data using charts and graphs

To make predictions or generalizations about a population based on a sample

To summarize the main features of a collected dataset

To clean and preprocess data for machine learning models

GIAC Machine Learning Engineer

Domain 1Objective 4

Statistics Fundamentals GMLE Practice Questions (Page 10)

Part of the Foundational Data Science and Statistics domain, which makes up ~41% of our current practice bank. GIAC (SANS) does not publish an official question count, but from its 180-minute exam (~70–120 total, ~29–49 in this domain), expect 7–12 from this objective — we provide 49 practice questions to prepare you well beyond it. (estimate)

49questions here

10free pages

10concepts

Questions 46–49

46expert · hard
A data scientist wants to estimate the average height of all employees in a large multinational company. They collect a sample by selecting every 10th name from an alphabetical list of employees. Which potential bias is most likely to affect this estimate?
Select an answer first
47foundation · easy
What happens to the width of a confidence interval for a population mean when the sample size increases, assuming the confidence level remains the same?
Select an answer first
48application · medium
A data scientist at a retail company runs an A/B test to compare two website layouts. The p-value for the conversion rate difference is 0.04, and the 95% confidence interval for the difference is [0.001, 0.02]. The business team wants to launch the new layout. Which additional consideration is most important before deciding to launch?
Select an answer first
49foundation · easy
What is the primary purpose of inferential statistics?
Select an answer first

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