Answers IQ test

Question 15

image/svg+xml 3 -5 9 -5/2 81 -5/4 6561 ?
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 multiplying the previous number with itself. You find the second number in the sequence by multiplying the first number with itself: 3 * 3 = 9 You find the third number by multiplying the second number with itself: 9 * 9 = 81 etc.
VThe following applies to the numbers in the even positions:
In this sequence you find the next number by applying the following transformation: /2
image/svg+xml 3 -5 9 -5/2 81 -5/4 6561 ? *3 /2 *9 /2 *81 /2

Question statistics

Overview
Question ID: X5PTSuFy
Main category: Numerical Reasoning
Sub category: Number sequences
Difficulty Level: 11What is item difficulty?
Nr of times answered: 3252
Average IQ of people who answered this question: 104.19
Percentage of answers correct: 62.58%
Item Response Theory (IRT)What is Item Response Theory?
Item difficulty: 11 / 20What is item difficulty?
Discrimination: 1.96 What is item discrimination?
Point of Maximum Information: 99.67 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 3252 individual test takers who have answered this question.
Distractor AnalysisWhat is distractor analysis?
Average IQ of people who gave the correct answer: 107.00 Why does the average IQ of people who answer the questions differ per question?
Average IQ of people who gave an incorrect answer: 99.17
Percentage per answer
The graph illustrates the percentage of individual test takers, 3252 in total, who selected each answer option for this question.
Average IQ per answer
The graph displays the average IQ of test takers who chose each answer option. In an effective question, the average IQ of test takers who selected the correct answer should be significantly higher than that of test takers who selected the other options, also known as distractors.
Response Time AnalysisWhat is response time analysis?
Optimal time to spend on question: 42 seconds What is the optimal response time?
Optimal time to spend on question
The graph illustrates the last 250 correct and incorrect answers to this question, as well as the time it took for test takers to arrive at the answer. Using this data, an average optimal time for answering the question is calculated. However, it should be noted that the optimal time may vary for individual test takers.

Time spent: you used 35 seconds to answer this question