3.1
13 Mean = $2025.25, Median = $2209, Mode = None
14 Mean = $41.41, Median = $40.76, Mode = None
15 Mean = 3670 psi, Median = 3830 psi, Mode = 4090 psi
16 Mean = 266 Median = 266 Mode = 260
17 a. The mean is greater than the median because there is a greater frequency of lower numbers, resulting in a higher mean.
The mean is approximately equal to the median because there is a greater frequency of middle numbers, which results in the average being somewhere around the median.
The mean is less than the median because there is a higher frequency of higher numbers, resulting in a lower mean.
3.2
5 Standard deviation = 144/4 = (square root of)36 = 6
Sample variance = 36
6 Standard deviation = 400/4 = (square root of)100 = 10
Sample variance = 100
7 Standard deviation = 80/5 = (square root of)16 = 4
Population variance = 16
8 Standard deviation = 576/9 = (square root of)64 = 8
Population variance = 64
9 Standard deviation = 1764/9 = (square root of)196 = 14
Sample variance = 196
10 Standard deviation = 150/6 = (square root of)25 = 5
Population variance = 25
14 Range = (282-257) = 25
Sample standard deviation = 426/6 = (square root of)71 = 8.4
24 a. Sample standard deviation = 1680/43 = (square root of)39.07 = 6
The histogram is roughly bell shaped, so the use of the Empirical Rule is appropriate.
Roughly 96%
93.2%
Roughly 18%
11.4%