Answers IQ test

Question 18

image/svg+xml 3 -2 9 -1/3 15 -1/18 21 ?
What is the next number in this sequence?

Explanation

In this sequence there are actually two sequences. 1 sequence for the numbers in odd positions (1,3,5 enz) and one sequence for the numbers in the even positions (2,4,6 enz.) The following applies to the numbers in the odd positions:
In this sequence you find the next number by applying the following transformation: +6
VThe following applies to the numbers in the even positions:
In this sequence you find the next number by applying the following transformation: /6
image/svg+xml 3 -2 9 -1/3 15 -1/18 21 ? +6 /6 +6 /6 +6 /6

Question statistics

Overview
Question ID: hgsLYeJ3
Main category: Numerical Reasoning
Sub category: Number sequences
Difficulty Level: 17What is item difficulty?
Nr of times answered: 1295
Average IQ of people who answered this question: 119.76
Percentage of answers correct: 46.87%
Item Response Theory (IRT)What is Item Response Theory?
Item difficulty: 17 / 20What is item difficulty?
Discrimination: 2.19 What is item discrimination?
Point of Maximum Information: 122.55 What is Point of Maximum Information?
Item Characteristic Curve (ICC)
This Item Characteristic Curve shows the probability that a person with a given IQ level will correctly answer this question. This graph is based on the answers and the IQ levels of 1295 individual test takers who have answered this question.
Distractor AnalysisWhat is distractor analysis?
Average IQ of people who gave the correct answer: 122.92 Why does the average IQ of people who answer the questions differ per question?
Average IQ of people who gave an incorrect answer: 116.53

Time spent: you used 56 seconds to answer this question