Statistics

Q1.For 30 students with marks: 10(1), 20(1), 36(3), 40(4), 50(3), 56(2), 60(4), 70(4), 72(1), 80(1), 88(2), 92(3), 95(1). The exact mean is:

• A59.3
• B62
• C57
• D65

Q2.The mean of observations x₁, x₂, ..., xₙ with frequencies f₁, f₂, ..., fₙ using the direct method is:

• AΣfᵢ / Σxᵢ
• BΣfᵢxᵢ / Σfᵢ
• CΣfᵢxᵢ / n
• DΣxᵢ / n

Q3.For which type of data is mode the most appropriate measure of central tendency?

• AFinding average wage of workers
• BFinding the most popular T.V. programme
• CComparing performance of two schools
• DFinding average height of students

Q4.Household monthly expenditures: 1000–1500(24), 1500–2000(40), 2000–2500(33), 2500–3000(28), 3000–3500(30), 3500–4000(22), 4000–4500(16), 4500–5000(7). Modal class is:

• A1000–1500
• B1500–2000
• C3000–3500
• D2500–3000

Q5.Number of heartbeats per minute for 30 women: 65–68(2), 68–71(4), 71–74(3), 74–77(8), 77–80(7), 80–83(4), 83–86(2). The mean heartbeats using step-deviation (a=75.5, h=3) is:

• A75.9
• B74.5
• C76.5
• D73