Question 48
Measures of Central TendencyUse the following information to answer questions 48 and 49.
Fifty boxes each of 50 bolts were inspected for the number which were defective. The following was the result
No. of defective per box: 4, 5, 6, 7, 8, 9
No. of boxes: 2, 7, 17, 10, 8, 6
The mean and the median of the distribution are respectively
- A.6.7, 6
- B.6.7, 6.5
- C.6, 6.7
- D.6.5, 6.7
Show the answer and explanation
Answer: A (6.7, 6)
Explanation
Σfx = 8 + 35 + 102 + 70 + 64 + 54 = 333 over 50 boxes, so the mean is 6.66 ≈ 6.7. The 25th and 26th boxes both have 6 defective (cumulative frequencies 2, 9, 26), so the median is 6.