Statistical Reports Worksheets Grade 11

1. Ava is evaluating a health news article that claims a new dietary supplement improves memory. The article cites a study where 85% of participants showed improved test scores after taking the supplement for six months. However, Ava notices the study was conducted with only 12 participants, all of whom were employees of the company that produces the supplement. Additionally, the article does not mention a control group or any blinding procedure. Identify at least two major statistical flaws in this study and explain why the claim might be misleading.
2. A study claims that 72% of students at a high school prefer online learning. The survey was conducted by asking 27 students in an advanced computer science class. Evaluate the validity of this claim.
3. A study claims that 85% of teenagers prefer online learning. The survey was conducted by a website selling online courses, with a sample size of 50 teenagers who visited their site. Evaluate the validity of this claim.

…and 4 more problems

1. log₂(8) + sin(π/6) = ?
2. Mere is evaluating a report from a local fitness company that claims their program helps people lose weight. The company surveyed 12 participants who completed their 8-week program. All 12 participants reported losing weight, with an average loss of 6 kg. The survey was conducted by emailing a link to a satisfaction questionnaire to all 120 people who had ever purchased the program, but only 12 responded. Evaluate the validity of the company's claim that the program is effective for weight loss, identifying any potential biases or issues with the data.
3. log₂(64) + cos(π/3) = ?

…and 4 more problems

1. A news report claims that 90% of high school students in a city get at least 8 hours of sleep per night. The claim is based on a survey of 20 students who were approached outside a local gym at 6:00 AM. Evaluate the validity of this claim, considering potential sources of bias and the adequacy of the sample size.
2. A study claims that 82% of students at a high school prefer online learning. The study surveyed 50 students who were all members of the school's computer club. Evaluate the validity of this claim.
3. Sophia is evaluating a news report that claims 'A new study of 12 students found that 100% of participants improved their test scores after using a new study app. Therefore, the app is guaranteed to improve test scores for all students.' Identify at least two major statistical flaws in this claim and explain why the conclusion is not valid.

…and 3 more problems