# Statistics and the weather (Investigation)

Lesson

## Different types of variables

According to the Australian Bureau of Statistics, numeric variables have values that describe a measurable quantity as a number, like 'how many' or 'how much'. They are therefore quantitative variables, which can take on either continuous or discrete values.

Categorical variables, on the other hand, are qualitative variables that describe a quality or characteristic, like 'what type' or 'which category'. Sometimes, these variables can take on values that are logically ordered, such as small, medium and large sizes in clothing. In this case, they are called ordinal variables. However, nominal variables, such as eye colour, take on values that cannot be organised in a logical sequence.

## Exercise

Go to http://www.climate-charts.com/world-index.html and select a city from each continent. Answer the following questions with reference to your 7 selected cities.

1. Which one of these has the:

• highest maximum temperature?
• lowest maximum temperature?
• lowest minimum temperature?
• highest minimum temperature?
• largest range between its maximum and minimum temperatures?
• highest monthly rainfall?
• the largest range between its highest monthly rainfall and its lowest?
2. Write a summary of the climatic patterns of one city for a tourist who has never visited the city and is keen to know what the climate is like in order to know what clothes to pack for his upcoming year-long trip.

3. Which city do you regard as having the most pleasant climate conditions to live in? Which feature(s) of the climate was the most important to your choice?

4. Is there any relation between how close cities are to each other and how similar their climate patterns are? If so, investigate why this relation exists.

• Which cities have large temperature variations throughout the year?
• Which cities have small temperature variations throughout the year? Of these cities, which are hot throughout the whole year? Which are cold throughout the whole year?
• Investigate why some cities have large temperature variations while others have small variations.
• Rank the 7 cities from hottest to coldest. Why is the city in Africa so hot and the city in Antarctica so cold? Investigate what factors influence the temperature levels (not variations) of a city.

• Which cities have large rainfall variations throughout the year?
• Which cities have comparatively small rainfall variations?
• Investigate why such differences in rainfall patterns exist.
• In which cities are rainfall patterns and temperature variation closely related?
• In which cities are they not?
• Investigate reasons for these differing relations.
• Which cities have four seasons?
• Are the seasons aligned in all these cities? If not, what is the reason for the different alignment of seasons?
• Which cities have only two seasons (rainy and dry)?
• Are the seasons aligned in all these cities? If not, what is the reason for the different alignment of seasons?
• What is the reasoning behind the different number of seasons among cities?
• Which cities have 24-hour daylight (or very close to 24-hour daylight) during some periods of the year and no daylight (or very close to no daylight) during others?
• What factors determine when each of these two periods occurs?
• What factors determine whether a city has such extremes of daylight or whether it has more common daylight patterns like that in Sydney?