Lesson 4

In Try This 3 you may have noticed that using the value of 75 lightning strikes per year to calculate the odds of lightning striking on a random day was not reasonable. One reason why this is not a good measure is that lightning is much more common during the summer months than during the winter. Also, lightning may strike multiple times on some days; therefore, there will be fewer than 75 days per year that lightning occurs.

Weather information resembling that in the previous table, “Average Days of Precipitation Per Year for Toronto,” is useful for long-term predictions. However, a weather forecast would likely provide better information for the immediate future.

Self-Check 2

Source: 2001 Census of Canada and 2006 Census of Canada, (Statistics Canada, 2001 and 2006), < http://www12.statcan.ca> (11 March 2012).

© Iryna Volina/18675311/Fotolia

Use the information from the map and the graph to complete the following questions. Open “Map of Provinces and territories of Canada” to see a larger version of the map.

1. A person migrated between Alberta and Ontario in 2004. What are the odds that she moved from Alberta to Ontario? Answer
2. A Canadian from outside Alberta migrated to Alberta. What is the probability that he was from Newfoundland? Answer
3. Suppose 472 people moved out of Alberta today. How many of these do you expect moved to British Columbia? Answer
4. Explain whether or not it is reasonable to use the table with information from 2001–2006 to make predictions for today. Answer