Question 1: A class took a quiz, and the scores were categorized as follows: 10 students scored 50, 15 students scored 60, 8 students scored 70, and 7 students scored 80. Calculate the mean score for the class.

Answer: 64

Question 2: The table shows the number of books read by students in a month: 4 students read 2 books, 6 students read 4 books, 5 students read 6 books, and 3 students read 8 books. Find the average number of books read per student.

Answer: 5

Question 3: In a survey, 12 people preferred tea, 18 preferred coffee, and 10 preferred juice. The number of cups each person drinks per day was: tea - 1, coffee - 2, juice - 3. Calculate the overall average cups consumed per person.

Answer: 2.2

Question 4: A store recorded the number of items sold each day for a week: Mon- 20, Tue- 25, Wed- 18, Thu- 22, Fri- 30, Sat- 27, Sun- 24. What was the average number of items sold per day?

Answer: 23.3

Question 5: A factory produces different batches of gadgets with the following quantities: Batch 1 - 150 units, Batch 2 - 200 units, Batch 3 - 180 units, Batch 4 - 220 units. Find the mean production per batch.

Answer: 187.5

Question 6: The table shows the number of hours students spend on homework: 5 students spend 2 hours, 7 students spend 3 hours, 4 students spend 4 hours, and 4 students spend 5 hours. Calculate the average homework time.

Answer: 3.3

Question 7: A sports club recorded the distances run by members in a month (km): 3 members ran 50 km, 5 members ran 60 km, 4 members ran 70 km, 2 members ran 80 km. Find the mean distance run by a member.

Answer: 62.5

Question 8: A survey found that 9 people preferred apples, 12 preferred bananas, and 8 preferred oranges. Each person, on average, eats: apples - 3, bananas - 2, oranges - 4. What is the overall average fruit intake per person?

Answer: 2.7

Question 9: A bakery baked different quantities of bread each day: Mon- 80, Tue- 90, Wed- 85, Thu- 95, Fri- 100. Calculate the average bread baked per day.

Answer: 90

Question 10: The number of tickets sold at a cinema over 5 days was: 150, 180, 200, 170, 160. What is the mean number of tickets sold per day?

Answer: 172

Question 11: In a class, students' scores are grouped as follows: 8 students scored 55, 10 students scored 65, 7 students scored 75, and 5 students scored 85. Find the mean score.

Answer: 67.5

Question 12: Identify a common mistake made when calculating Σfx / Σf and explain how to correct it.

Answer: Mistake: Adding only the midpoints instead of multiplying scores by frequencies. Correction: Always multiply each score by its frequency before summing.