Name_________________________________________________________
CCSS
6.SP.5
Date __________
Speed
A traffic camera records the speeds (in miles per hour) of motorists along a
stretch of highway. The results are shown.
68, 70, 65, 62, 58, 67, 72, 75, 72, 65, 68, 69, 75, 110, 68
60, 64, 62, 57, 60, 68, 100, 70, 68, 70, 72, 68, 70, 72, 67
1. Identify the number of motorists in the data set and make a
box-and-whisker plot for the data.
2. Find and interpret the range and interquartile range of the data.
3. The stretch of highway being recorded has a speed limit of 70 miles per hour.
The local highway authority will consider a speed limit change when 75% of
motorists are traveling at or below the given speed limit. Based on this data,
will a speed limit change be considered? Explain your reasoning.
4. Identify any outliers in the set of data. How does removing the outlier(s) affect
the box-and-whisker plot?
5. Does removing the outliers from the data set change your answer to
Exercise 3? Explain.
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Big Ideas Math
Performance Tasks
9
CCSS
6.SP.5
6.SP.5
Common Core State Standard
Summarize numerical data sets in relation to their context, such as by:
a. Reporting the number of observations.
b. Describing the nature of the attribute under investigation, including
how it was measured and its units of measurement.
c. Giving quantitative measures of center (median and/or mean) and
variability (interquartile range and/or mean absolute deviation), as well
as describing any overall pattern and any striking deviations from the
overall pattern with reference to the context in which the data were gathered.
d. Relating the choice of measures of center and variability to the shape
of the data distribution and the context in which the data were gathered.
CCSS
6.SP.5
Grading Rubric
Answers
Score
1. 30; Student draws box-and-whisker plot appropriately for the
following points: least value = 57, first quartile = 65, median = 68,
third quartile = 72, and greatest value = 110.
2
2. range = 53 miles per hour; interquartile range = 7 miles per hour;
4
The speeds vary by no more than 53 miles per hour. The middle
half of the speeds vary by no more than 7 miles per hour.
3. no; The third quartile is 72. So, 75% of the recorded speeds are
2
72 miles per hour or less.
4. 100 and 110; The first and third quartiles and the greatest value
2
have changed. The length of the right whisker is much shorter.
5. yes; The third quartile of the box-and-whisker plot is 70. So,
2
75% of the motorists are traveling at or below 70 miles per hour.
Precision
1. Student reports the number of observations and uses quartiles to
2
construct a box-and-whisker plot.
2. Student uses ordered data to find and interpret the range and the
2
interquartile range.
3. Student understands how the data are distributed.
1
4. Student identifies the outliers and how they affect the data display.
2
5. Student recognizes how removing outliers affects the third quartile.
1
Total Points
10
Big Ideas Math
Performance Tasks
20
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