How to Measure Anything Workbook: Finding the Value of Intangibles in Business

CHAPTER 9 Sampling Reality: How Observing Some Things Tells Us about All Things

1. B
2. False. You should narrow it.
3. True
4. A
5. A
6. False
7. E
8. A
9. B
10. True
11. A
12. C

13. D

    Upper Bound on Chart = about 2

    Lower Bound on Chart = about 0.075

    Max Serial Number – Min Serial Number = 10107348 – 10085197 = 22,151

    Upper Bound Estimate = 22,151 × (1 + 2) = 66,453

    Lower Bound Estimate = 22,151 × (1 + .075) = 23,812

14. B
15. C

16. A

    The variance is equal to the square of the standard deviation.

    Divide the sample variance by the number in each sample:

    3,000² / 40 = 225,000

    3,041.38² / 70 = 132,142.86

    Add the two from above:

    225,000 + 132,142.86 = 357,142.86

    Find the square root of the result:

    Sqrt(357,142.86) = 597.61

    Compute the difference of sample means:

    35,000 – 34,000 = 1,000

    Chance that the mean revenue produced by extroverts is lower than that of nonextroverts = Normdist(0, 1000, 597.61, 1) = 4.7%

17. A
18. B
19. A. Recall that a negative correlation is not the same as weakly correlated. It means that as one variable increases, the other decreases. A correlation of -.98 means that when one variable increases the other decreases in a highly predictable way.
20. C
21. True

22. Sample Mean (point estimate) = (70 + 73 + 75 + 71 + 80)/5 = 73.8

    Standard error of the estimate of the mean =SQRT(VAR (70,73,75,71,80)/5)^.5 = 1.772

    t = 2.13 (given)

    90% CI for Mean = Point Estimate ± t × Stdev

    90% CI for Mean = 73.8 ± 2.13 × 1.77 = 70 to 77.6

23. 936 – 1,587

    Stdev of Proportion = Sqrt(P × (1 - P))

    Proportion Tagged = 34/200 = 0.17

    Stdev of Proportion Tagged ...