StatsTest1 2
Math 136, Fall 2013 Test 1, Chapters 2 - 4
Show all work in a Blue Book. Problems are worth 12 points each unless indicated otherwise. Box your final answer.
1. For each of the following terms give a definition and an example.
a) interquartile range
b) residual
c) voluntary response bias
d) placebo
2. (13 points) The frequency table below summaries the horsepower of 50 cars.
Horsepower
Frequency
80
7
90
13
100
12
110
7
120
4
130
3
140
2
150
1
160
0
170
1
a) Construct a histogram.
b) Find the mean, median, standard deviation, and IQR.
c) Describe the distribution’s shape, center, and spread. Justify your answer.
d) Add a column to the table for relative frequency.
e) Add another column to the table for cumulative relative frequency.
f) What is the 86th percentile?
3. (13 points) An automobile brake and muffler shop reported the following repair bills for their customers yesterday.
88 203 283 118 312 143 290 252 172 227 154 56 480 192 381 292 346 213 181 422
a) Stem and leaf plot
b) Find the five number summary.
c) Construct a complete boxplot and determine if the data is skewed to the left, skewed to the right, or symmetric.
d) Would any of the bills be considered an outlier? If so, which bill(s)? Justify your answer.
4. (13 points) ACT scores are approximately normally distributed, with mean 20 and standard deviation 6.
a) Between which two ACT scores would you expect to find the middle 90%?
b) What percentage of scores are between 16 and 26?
c) What percentage of scores are above 22?
d) What percentage of scores are below 13?
5. The mean height of a class of 30 children is 53 in., the median is 49 in., the standard deviation is 2.7. in., and the interquartile range is 3.5 in.
a) Find the mean, standard deviation, median, and interquartile range if each child grows 3 in.
b) Find the mean, standard deviation,
Show all work in a Blue Book. Problems are worth 12 points each unless indicated otherwise. Box your final answer.
1. For each of the following terms give a definition and an example.
a) interquartile range
b) residual
c) voluntary response bias
d) placebo
2. (13 points) The frequency table below summaries the horsepower of 50 cars.
Horsepower
Frequency
80
7
90
13
100
12
110
7
120
4
130
3
140
2
150
1
160
0
170
1
a) Construct a histogram.
b) Find the mean, median, standard deviation, and IQR.
c) Describe the distribution’s shape, center, and spread. Justify your answer.
d) Add a column to the table for relative frequency.
e) Add another column to the table for cumulative relative frequency.
f) What is the 86th percentile?
3. (13 points) An automobile brake and muffler shop reported the following repair bills for their customers yesterday.
88 203 283 118 312 143 290 252 172 227 154 56 480 192 381 292 346 213 181 422
a) Stem and leaf plot
b) Find the five number summary.
c) Construct a complete boxplot and determine if the data is skewed to the left, skewed to the right, or symmetric.
d) Would any of the bills be considered an outlier? If so, which bill(s)? Justify your answer.
4. (13 points) ACT scores are approximately normally distributed, with mean 20 and standard deviation 6.
a) Between which two ACT scores would you expect to find the middle 90%?
b) What percentage of scores are between 16 and 26?
c) What percentage of scores are above 22?
d) What percentage of scores are below 13?
5. The mean height of a class of 30 children is 53 in., the median is 49 in., the standard deviation is 2.7. in., and the interquartile range is 3.5 in.
a) Find the mean, standard deviation, median, and interquartile range if each child grows 3 in.
b) Find the mean, standard deviation,