What does effect size measure in a statistical analysis?

The sample size needed to achieve significance

The magnitude of the difference or relationship, independent of sample size

The probability of making a Type I error

A data scientist builds a model to predict delivery times and computes a 95% confidence interval for the mean delivery time of [28.4, 31.6] minutes based on a sample of 200 deliveries. The operations manager asks what this interval means. Which interpretation is correct?

If we repeatedly sampled 200 deliveries and computed the interval the same way, about 95% of such intervals would contain the true population mean.

There is a 95% probability that any single future delivery will take between 28.4 and 31.6 minutes.

95% of all deliveries in the population take between 28.4 and 31.6 minutes.

The true population mean has a 95% chance of falling between 28.4 and 31.6 minutes.

What does a 95% confidence interval for a population mean represent?

There is a 95% probability that the sample mean falls within this interval

If we repeated the sampling process many times, approximately 95% of the calculated intervals would contain the true population mean

95% of the data values in the population fall within this interval

There is a 95% probability that the true population mean is outside this interval

A healthcare analyst wants to compare patient satisfaction scores (0–100 scale) across three different hospital departments. The scores for each department are heavily skewed to the left, and the sample sizes are small (n = 12, 15, and 10). Which test is most appropriate for comparing the central tendency of these three groups?

Chi-square test of independence

Which test is used to determine if there is a significant association between two categorical variables?

Chi-square test of independence

CertNexusCertified Data Science Practitioner (CDSP)

Domain 5Objective 5

Statistics CERTIFIED-DATA-SCIENCE-PRACTITIONER Practice Questions (Page 3)

Part of the 5.0 Testing models domain, which accounts for 4-7% of the CERTIFIED-DATA-SCIENCE-PRACTITIONER exam.

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Questions 11–15

11foundation · medium
What does effect size measure in a statistical analysis?
Select an answer first
12application · medium
A data scientist builds a model to predict delivery times and computes a 95% confidence interval for the mean delivery time of [28.4, 31.6] minutes based on a sample of 200 deliveries. The operations manager asks what this interval means. Which interpretation is correct?
Select an answer first
13foundation · medium
What does a 95% confidence interval for a population mean represent?
Select an answer first
14application · medium
A healthcare analyst wants to compare patient satisfaction scores (0–100 scale) across three different hospital departments. The scores for each department are heavily skewed to the left, and the sample sizes are small (n = 12, 15, and 10). Which test is most appropriate for comparing the central tendency of these three groups?
Select an answer first
15foundation · medium
Which test is used to determine if there is a significant association between two categorical variables?
Select an answer first

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