7th Grade Math

502 Statistical Displays

For each data set, find the median, the upper and lower quartiles, and the

interquartile range.

7. daily attendance at the water park: 346, 250, 433, 369, 422, 298


8. texts per day: 24, 53, 38, 12, 31, 19, 26


9. cost of admission: $13.95, $24.59, $19.99, $29.98, $23.95, $28.99


10. SCIENCE The table shows the number of Known Moons of Planets
    Mercury 0 Jupiter 63
    Venus 0 Saturn 34
    Earth 1 Uranus 27
    Mars 2 Neptune 13

known moons for each planet in our solar

system. Use the measures of variation to

describe the data.

1111 EXERCISE Lucy and Dena are training for a bike race and recorded their

mileage for a week. Find the measures of variation of each person’s

mileage. Which measures of variation show the girls’ similarities in their

training? the differences? Explain.

Monday Tuesday Wednesday Thursday Friday Saturday Sunday

Lucy 7 mi 3 mi 5 mi 8 mi 6 mi 10 mi 9 mi

Dena 6 mi 4 mi 6 mi 8 mi 11 mi 9 mi 7 mi

C 12. FIND THE ERROR Hiroshi was finding the measures of variation of the

following set of data: 89, 93, 99, 110, 128, 135, 144, 152, and 159. Find his

mistake and correct it.

median = 128

lower quartile = 99

upper quartile = 144

interquartile range = 45

range = 70

13. OPEN ENDED Create a list of data with at least six numbers that has an
    interquartile range of 15 and two outliers.


14. E WRITE MATH Explain why the median is not affected by very high
    or very low values in the data.

Real-World Link

The average

twelve-year-old

should spend

about one hour

a day doing

moderate to

intense physical

activity.

RR

T

B

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