Data Science Data Science Statistical Concepts and Inference Questions and Answers 3

Question 1

A machine learning model yields a p-value of 0.03 when testing whether a new feature improves prediction accuracy. With alpha = 0.01, what is the correct conclusion?

Accepted Answer

Fail to reject the null hypothesis because 0.03 > 0.01

Answer

Since the p-value of 0.03 exceeds the significance level of 0.01, we do not have sufficient evidence to reject the null hypothesis at that threshold.

Question 2

What does the Central Limit Theorem guarantee about the sampling distribution of the sample mean?

Accepted Answer

It approaches a normal distribution as sample size increases, regardless of population shape

Answer

The Central Limit Theorem states that the distribution of sample means approaches normality as sample size grows, even if the underlying population is non-normal.

Question 3

In Bayesian inference, what role does the prior distribution play?

Accepted Answer

It encodes beliefs about a parameter before observing data

Answer

The prior distribution in Bayesian inference captures existing knowledge or beliefs about a parameter before any new data is collected.

Question 4

A correlation coefficient of r = -0.92 between two variables indicates which of the following?

Accepted Answer

A strong negative linear relationship

Answer

An r value of -0.92 indicates a strong negative linear association, meaning as one variable increases the other tends to decrease substantially.

Question 5

Which resampling technique estimates the variability of a statistic by repeatedly sampling with replacement from the observed data?

Accepted Answer

Bootstrap

Answer

The bootstrap method draws repeated samples with replacement from the original dataset to estimate the sampling distribution of a statistic.

Data Science Practice Test

Data Science Practice Test

Data Science Data Science Statistical Concepts and Inference Questions and Answers 3