Share
Explore BrainMass

Frequency Distribution and Measures of Variation

Pandas: The size of the home ranges (in square kilometers) of several pandas were surveyed over a year's time, with the following results.

Home Range Frequency
.1-.5 11
.6-1.0 12
1.1-1.5 7
1.6-2.0 6
2.1-2.5 2
2.6-3.0 1
3.1-3.5 1

Sketch a histogram and frequency polygon for the data.

28. Life of Light Bulbs: A certain type of light bulb has an average life of 500 hours, with a standard deviation of 100 hours. The length of life of the bulb can be closely approximated by a normal curve. An amusement park buys and installs 10,000 such bulbs.

Find the shortest and longest lengths of life for the middle 80% of the bulbs.

See attached file for full problem description.

9.1 - Question #40
9.3 - Question #28

Solution Preview

For #40, I made the chart in Excel. A histograph is a bar chart in which the height of the bars represents the frequency for each category (this is in pink in the chart). A frequency polygon is made by connecting the points that have the center of the category intervals as their x-coordinate and the frequency as their y-coordinate (this is in blue in the chart).

For #28, the text is also in the ...

\$2.19