Section 1.1: The Most Popular News Statistics

Americans Without Health Insurance  In 2004 there were Americans without health insurance per 1000 American. How large is this number? Is the number of Americans without health insurance roughly equal to the population of Canada? Ireland? Mexico? China? Spain? What information do you need to answer this question?

Population Sizes  Ireland – 4 million  Mexico – million  Canada – 32.8 million  China – 1.3 billion  Spain – 40.3 million How can we use these numbers to compare them to the US population without healthcare?

How do we write a proportion as a decimal? “155.3 per 1000” is a proportion. To write it as a decimal do the following: So 15.53% of all Americans are without health care. Given that there are roughly 295 million Americans, rough how many are without health care?

Practice  In 2002 (in the U.S.A.) there were deaths per 100,000 people. The population in 2002 was approximately million people. Approximately how many deaths occurred in 2002?

Recap: Convert a proportion to a raw count  Multiply proportion by total count.

Why does one report proportions rather than total counts?  Proportions allow you to compare across different sized groups.  Example: 34,788,000 whites are without health insurance while 7,186,000 blacks are without health insurance. How do these compare?

 There are approximately 241million white Americans and 38 million black Americans.  Solve the problem.

Comparing Proportions and Raw Counts Using Pictures  Pie Charts – Favorite Type of Music for a Sample of Teenagers

Bar Graphs 

Bar Charts  New England Patriots Regular Season

Where did this data come from? 

Proportions vs. Raw Counts  Proportions look different than raw numbers since a proportion is the number in a small group divided by the total number in the big group.  With a large sample, proportions make things look smaller and counts make things look bigger.  E.g. 0.8% of Americans died in 2004.

 With a small sample, proportions make things look bigger and counts make things look smaller.  e.g. 80% of Dentist’s prefer Crest toothpaste.