A data analyst is examining a dataset of employee salaries. The mean salary is $75,000, the median is $60,000, and the mode is $55,000. Which statement about the distribution is most accurate?

The distribution is symmetric around the mean.

The distribution is bimodal with two distinct peaks.

The distribution is left-skewed, likely due to a few low salaries.

The distribution is right-skewed, likely due to a few high salaries.

A/B test on a website shows a 2% increase in click-through rate with a p-value of 0.01. The team also computes a 95% confidence interval for the true lift: [0.5%, 3.5%]. Which interpretation is correct?

The true lift is likely between 0.5% and 3.5%, and the result is statistically significant.

The result is not significant because the interval includes values below 1%.

There is a 95% chance the true lift is exactly 2%.

The p-value of 0.01 means there is a 1% chance the true lift is zero.

A data team is comparing two models' accuracy. Model A has an accuracy of 90% with a 95% confidence interval of [88%, 92%]. Model B has an accuracy of 91% with a 95% confidence interval of [89%, 93%]. The intervals overlap. Which conclusion is most appropriate?

Model A is significantly better because its interval is narrower.

The models are identical because the intervals overlap.

The difference in accuracy is not statistically significant at the 5% level, so the models are likely similar.

Model B is significantly better because its accuracy is higher.

A public health researcher wants to estimate the average blood pressure of adults in a large city. They have a list of all registered addresses. To ensure every adult has an equal chance of being selected, which sampling method should they use?

Stratified sampling by age group

Simple random sampling from the list of addresses

Systematic sampling by selecting every 10th address

Convenience sampling from a local clinic

GIAC Machine Learning Engineer

Domain 1Objective 4

Statistics Fundamentals GMLE Practice Questions (Page 8)

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 36–40

36expert · hard
A medical test for a rare disease has a sensitivity of 99% and a specificity of 95%. The disease prevalence is 0.1%. A patient tests positive. What is the probability that the patient actually has the disease?
Select an answer first
37application · medium
A data analyst is examining a dataset of employee salaries. The mean salary is $75,000, the median is $60,000, and the mode is $55,000. Which statement about the distribution is most accurate?
Select an answer first
38application · medium
A/B test on a website shows a 2% increase in click-through rate with a p-value of 0.01. The team also computes a 95% confidence interval for the true lift: [0.5%, 3.5%]. Which interpretation is correct?
Select an answer first
39expert · hard
A data team is comparing two models' accuracy. Model A has an accuracy of 90% with a 95% confidence interval of [88%, 92%]. Model B has an accuracy of 91% with a 95% confidence interval of [89%, 93%]. The intervals overlap. Which conclusion is most appropriate?
Select an answer first
40application · medium
A public health researcher wants to estimate the average blood pressure of adults in a large city. They have a list of all registered addresses. To ensure every adult has an equal chance of being selected, which sampling method should they use?
Select an answer first

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