Prediction: Error Analysis & Misconceptions
Mathematics
Year 9
12 questions
~24 mins
1 views0 downloads
About This Worksheet
A worksheet focusing on the concept of prediction in probability, highlighting common errors and misconceptions. Includes procedural practice, real-world scenarios, and challenging extension questions.
Worksheet Preview
Full preview • 12 questions
Prediction: Error Analysis & Misconceptions
Subject: MathematicsGrade: Year 9
Name:
Date:
TeachWhizzTeachWhizzTeachWhizzTeachWhizzTeachWhizzTeachWhizzTeachWhizzTeachWhizzTeachWhizzTeachWhizzTeachWhizzTeachWhizzTeachWhizzTeachWhizzTeachWhizzTeachWhizzTeachWhizzTeachWhizzTeachWhizzTeachWhizzTeachWhizzTeachWhizzTeachWhizzTeachWhizzTeachWhizzTeachWhizzTeachWhizzTeachWhizzTeachWhizzTeachWhizzTeachWhizzTeachWhizzTeachWhizzTeachWhizzTeachWhizzTeachWhizzTeachWhizzTeachWhizzTeachWhizzTeachWhizz
Untitled Worksheet
Grade Year 9
A
Introduction
Read the key concept below before attempting the questions.
1.
Expected frequency is calculated using the formula: Expected Frequency = Total Number of Trials × Probability of an Event. This allows us to predict how often an event should occur in repeated trials.
[2 marks]B
Practice Questions
Answer all questions. Show your working in the grid spaces provided.
1.
A bag contains 5 red balls and 15 blue balls. If a ball is randomly selected 60 times, estimate the expected number of red balls drawn.
[3 marks]2.
In a survey, the probability of a student choosing to study mathematics is 0.25. If 120 students are surveyed, what is the expected number of students who choose mathematics?
[3 marks]3.
Calculate the expected frequency of a rare event that occurs with a probability of 0.02 in 500 trials.
[4 marks]4.
A fair die is rolled 240 times. What is the expected number of times a 4 will appear?
[3 marks]5.
If the probability of rain tomorrow is 0.3, predict the expected number of rainy days in a 30-day month.
[3 marks]6.
A factory produces 200 widgets, with a defect rate of 2%. What is the expected number of defective widgets?
[3 marks]7.
A card is drawn from a standard deck 50 times. The probability of drawing an ace is 4/52. Estimate the expected number of aces drawn.
[3 marks]8.
A survey shows that 60% of people prefer coffee over tea. If 150 people are surveyed, what is the expected number who prefer coffee?
[3 marks]9.
A machine produces 1000 items, with a defect probability of 0.005. Calculate the expected number of defective items.
[4 marks]10.
A student flips a coin 150 times. What is the expected number of heads?
[3 marks]11.
Common mistake: A student calculates expected frequency as Total Trials ÷ Probability. Explain why this is incorrect and provide the correct formula.
[2 marks]Quick Actions
What is Remix?
Create a new worksheet based on this one. Change the grade level, topic, number of questions, or difficulty - then generate a fresh version.
- • Change grade level (Grade 6 → Grade 7)
- • Swap topics (Harry Potter → Macbeth)
- • Add more questions (10 → 15)
- • Adjust difficulty
Details
- Created
- 1/1/2026
- Updated
- 1/1/2026
- Type
- worksheet