Question 1: Calculate the bias percentage if a survey of 200 students favors a particular snack with 150 students choosing it. Show your working.

Answer: 25

Question 2: Construct a simple sample of 20 students from a class of 50, ensuring minimal bias in selection. Describe your method.

Answer: Random selection using a random number generator or lottery method to ensure unbiased sampling.

Question 3: If a survey only includes students from the front row of a classroom, explain what type of bias this introduces and why.

Answer: Selection bias, because students in the front may have different characteristics than those at the back, leading to unrepresentative results.

Question 4: Calculate the proportion of biased samples if 60 out of 100 samples favor a certain outcome due to a flawed sampling method.

Answer: 60%

Question 5: A school surveys students’ favorite sport by asking only students in the sports club. Identify the bias and suggest how to reduce it.

Answer: Selection bias; to reduce bias, include a random sample of students from all classes and interests.

Question 6: Plot the graph of the function y = 2x for x values from -5 to 5 on the grid provided.

Answer: Students will draw the line y=2x across the given range.

Question 7: Construct a triangle on the grid with sides measuring 3cm, 4cm, and 5cm. Label the sides.

Answer: Students will draw the triangle and label the sides accordingly.

Question 8: Identify the bias in a sample that only includes data collected from online surveys distributed via social media.

Answer: Sampling bias due to excluding individuals without internet access, leading to unrepresentative data.

Question 9: A researcher wants to minimize bias when collecting data about student study habits. List two strategies they could use.

Answer: Use random sampling; include diverse groups of students from different years and backgrounds.

Question 10: A survey shows 80% of students prefer online learning. The survey was only conducted in computer labs. What kind of bias might this introduce?

Answer: Sampling bias, as only students who use computer labs were surveyed, possibly excluding those who prefer traditional methods.

Question 11: Identify the error in this sampling method: collecting opinions from the first 50 students to enter the cafeteria.

Answer: Convenience bias; not representative of the entire student population, only those entering at a specific time.

Question 12: Explain how non-random sampling can lead to bias, with an example.

Answer: Non-random sampling can favor certain groups over others; for example, only surveying students in a particular class may exclude others with different opinions.