I'm studying for the CQT exam. According to the QCI Primer (7th edition, chapter 9, page 15), the number 2500 has just two significant digits - "no printed decimal point, count nonzero digits only."On the next page of the Primer it describes how to calculate with significant digits: "A good quick rule of thumb...is to identify the incoming data with the fewest significant figures and to report exactly one more figure in the final answer."
So, if I take 2500 inches, and calculate a conversion to feet, I divide by 12, I get the result 208.33333. Then for my final answer, I report 3 significant digits: 208 feet. Is this correct?
Next, I take the CQI practice exam on the CD-ROM that is presumably based on the Primer referenced above, and come across the following question:
A volume containing 100 cubic centimeters would convert to how many cubic inches?
A) 6 cubic inchesB) 6.1 cubic inchesC) 6.10 cubic inchesD) 6.102 cubic inchesMy answer, attempting to follow the instructions of the Primer, is to say 100 cubic centimeters has only 1 significant digit (counting nonzero digits only). Therefore, the answer should have 2 significant digits. So I choose answer B: 6.1 cubic inches.
However, this answer is marked as incorrect, and I am told: "Since the fewest incoming significant digit is three, four figures should be reported in the answer. Answer D is correct.
Am I missing something, or is there a contradiction between the Primer and the CD-ROM? I can't find an explanation of this in my other two books (ASQ Certified Quality Technician Handbook, or G. Griffith's The Quality Technician's Handbook - 4th edition).
I would like to know how to correctly answer this question if something like it comes up on the actual CQT exam.
Thank you Claire! Very helpful!