DA Statistical Analysis 2

Question 1

What is the interquartile range (IQR)?

Accepted Answer

The difference between Q3 and Q1

Answer

The IQR is calculated as Q3 minus Q1 and represents the spread of the middle 50% of the data.

Question 2

What type of analysis examines the relationship between a dependent variable and one or more independent variables?

Accepted Answer

Regression analysis

Answer

Regression analysis models the relationship between a dependent variable and one or more predictors to explain or predict outcomes.

Question 3

In a box plot, what does the line inside the box represent?

Accepted Answer

Median

Answer

The line inside the box of a box plot marks the median (Q2), the middle value of the dataset.

Question 4

What is Type I error in hypothesis testing?

Accepted Answer

Rejecting a true null hypothesis

Answer

A Type I error (false positive) occurs when a true null hypothesis is incorrectly rejected.

Question 5

Which test is appropriate for comparing proportions between two independent groups?

Accepted Answer

Chi-square test

Answer

The chi-square test of independence is used to determine if there is a significant association between two categorical variables or proportions.

DA - Data Analyst Practice Test