An "Ozone Hole" Is

question 244

Multiple Choice

An "ozone hole" is

• A) a region centered on the equator where ozone levels are always very low because of destruction by direct sunlight.
• B) a region of the stratosphere, often above the South Pole, where ozone levels occasionally drop to very low levels.
• C) the name given to small pits or holes on the aluminum surface of an aircraft, etched by the corrosive ozone encountered in the stratosphere and requiring regular maintenance.
• D) a permanent region of very low ozone content in the stratosphere centered over the South Pole that has been there for thousands of years; the resulting transparency to UV radiation accounts for the lack of life-forms there.

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Definitions:

Frequency Distribution

A statistical representation showing the number of occurrences of each distinct value in a set of data.

Median

The middle value of a data set, which separates the higher half from the lower half of the data set.

Mean

The arithmetic average of a set of numbers, calculated by adding them up and dividing by the number of figures.

Mean

The average value in a set of numbers, calculated by dividing the sum of all values by the count of those values.