Answers to Exercises
Contents 
Accuracy and Scientific Notation
1) 0
places, 3 sig. digits, 5.42 x 10^{4} 
2) 0 places, 5 sig. digits, 1.7846 x 10^{8} 

3) 7 places, 4 sig. digits, 2.314 x 10^{4} 
4) 5 places, 3 sig. digits, 9.80 x 10^{3} 

5) 3 places, 6 sig. digits, 1.32502 x 10^{2} 
6) 2 places, 4 sig. digits, 3.741 x 10^{1} 

7) 4 places, 4 sig. digits, 3.473 x 10^{1} 
8) 1 place, 5 sig. digits, 1.4453 x 10^{3} 

9) 4.897 
10) 245.12 
11) 83.1 
12) 0.432 
13) 110 
14) 27.34 
15) 539,500 
16) 4,390,000 
17) 0.00435 
18) 0.0006288 
19) 57,789 
20) 312,200 
21) 0.008324 
22) 0.0000769 

1) 
8 AM is more skewed, 9 AM has largest value, 9 AM has smallest value, 8 AM has largest median, 9 AM has largest range, 9 AM
has largest IQR 
2) 
11 AM is more skewed, 10 AM has largest value, 11 AM has smallest value, 10 AM has largest median, the ranges are the same and
11 AM has largest IQR. 
3) 
1 PM is
more skewed, the largest values are about the same, 2
PM has the smallest value, 1 PM has
largest median, 2 PM has the largest range and largest IQR. 
4) 
3 PM is more skewed, 3 PM has largest value, 4 PM has smallest value, 3 PM has largest median, 4 PM has the largest range
and IQR. 
5) 
5 PM is more skewed, 5 PM has largest value, 6 PM has smallest value, 5 PM has largest median, 5 PM has the largest range, the IQR's are about the same. 
1) 74.08 
2) 55.73 
3) 0.4733 
4) 0.1475 
5) 2.72 
6) 0.85 
7)
0.7171 
8) 0.7191 
9)
1,637,000 
10)
265,400 
11) 295.6 
12) 94.88 
Coefficients of Determination and
Correlation
1) 45.2% of the variation is explained by the regression line. 

2) 91.3% of the variation is explained by the regression line. 

3) 72.1% of the variation is explained by the regression line. 

4) 26.4% of the variation is explained by the regression line. 

5) weak
positive correlation 
6) no
correlation 
7) strong
positive correlation 
8)
perfect negative correlation 
9) moderate positive correlation 
10) moderate negative correlation 
11) no correlation 
12) strong negative correlation 
1) mean = 32.2, std. dev. = 11.1 
2) mean = 10.7, std. dev. = 9.6 
3) mean = 15.6, std. dev. = 10.8 
4) mean = 21.1, std. dev. = 11.7 
5) mean = 44.0, std. dev. = 10.6 
6) mean = 80.5, std. dev. = 8.1 
7) mean = 36.8, std. dev. = 7.6 
8) mean = 31.6, std. dev. = 5.2 
1) 
minimum =
18, maximum = 60, skewed left, one peak at 45,one gap between 24 and 30, no
extreme values 
2) 
minimum =
12, maximum = 108, skewed left, two peaks at 54 and 90, one gap between 24
and 36, no extreme values 
3) 
minimum = 0, maximum = 500, skewed right, one peak at 25, 3 gaps:
between 100 and 150, between 200 and 250, and between 300 and 400. Since the
last gap is twice as large, values between 400 and 500 are extreme. 
4) 
minimum = 15, maximum = 40, skewed right, two peaks at 27.5 and 37.5 (but the second peak is barely a peak), no gaps or extreme values. 
Outliers
and Influential Observations
1)
outlier near (12.9, 24.4), influential observation near (9.9, 16.1) 
2)
outlier near (112, 86), influential observation near (129, 121) 
3)
outlier near (53, 88), influential observations near (68, 108) and (76, 111) 
1) 
The
parameter is the average height of all women aged 20 years or older. 
The
statistic is the average height of 63.9 inches from the sample of 45 women. 

2) 
The parameter is the mean amount of sodium consumed by
children under the age of ten. 
The statistic is the mean of 2993 milligrams of sodium
obtained from the sample of 75 children. 

3) 
The parameter is the proportion of patients healed by Nexium in 8 weeks. 
The statistic is 213/224 = 0.951, the proportion healed in the sample. 

4) 
The
parameter is the average farm size in 
The
statistic is the mean farm size of 731 acres from the sample of 40 farms. 

5) 
The
parameter is the average oil output per well in the 

The
statistic is the mean oil output of 10.7 barrels per day from the sample of
50 wells. 
6) 
The parameter is the proportion of adults 18 or older who read a book in the previous year. 

The statistic is 835/1006 = 0.830, the proportion who read a book in the sample. 
7) 
The
parameter is the average amount of calcium that male teenagers consume. 

The
statistic is the mean of 1081 milligrams of calcium from the sample of 50
teenagers. 
8) 
The parameter is the proportion of adults with kids under 18
who ate together 7 days a week. 

The statistic is 337/1122 = 0.300, the proportion in the sample
who ate together. 
9) 
The parameter is the mean verbal SAT score for students
whose first language is not English. 

The statistic is the mean SAT verbal score of 458 from the sample of 20 students. 
1) 
Name  designator, Height  quantitative, River  qualitative, State 
qualitative, Completed  quantitative

2) 
No.  designator, Year  designator, Winner  qualitative, Winning
Score  quantitative, Loser  qualitative, Losing Score  quantitative,
Winning Coach  qualitative, Game Site  qualitative
