Chance and data

The modern world is an information world. Governments, credit bureaus, banks andmarketeers collect and use information about how we live, where we live, what we buy andwhat we desire. You can tap into information at home and elsewhere at any time using theInternet. We use statistics to collect, display and analyse information.Statistics and other information can be used to work out the probabilities of future events.In medicine, statistics and probability are used to investigate diseases and their treatment.Governments and other agencies use statistics and probability to decide where to put newdevelopments, and businesses use them to design ad campaigns and to target consumergroups for sales of particular products. Investors use statistics and probability to decidewhat stocks they should buy on the share market.

Collecting and displaying data

Statistical information is calleddata.The collection of data can be veryexpensive and time consuming, so itis important to collect only the datawe need.

Read Collecting and tabulating data

You may need to refer back to this later

Dicuss these and write down some suggestions in your book

Types of graphsCircle graphs (pie graphs or sector graphs), picturegraphs (pictograms or pictographs) and divided barcharts Draw a sketch of how these look

printed on a page

A histogram is a column graph used to show frequencies of grouped or ungrouped data.There is no gap between the columns because the data could be continuous. The scoregroups (such as 25–29, 30–34, etc.) are called classes. The actual upper and lowerboundaries of a class are called the upper class limit and lower class limit. A frequencypolygon is a line graph of frequencies, with points placed in the centres of class groups. It isusual to show frequencies of zero before the first class and after the last class.

A histogram is a column graph used to show frequencies of grouped or ungrouped data.There is no gap between the columns because the data could be continuous. The scoregroups (such as 25–29, 30–34, etc.) are called classes. The actual upper and lowerboundaries of a class are called the upper class limit and lower class limit. A frequencypolygon is a line graph of frequencies, with points placed in the centres of class groups. It isusual to show frequencies of zero before the first class and after the last class.

What do these look like?

The table below shows the temperature of a beaker of hot water as measured by students at2-minute intervals.a Draw a scatter graph of the results.b Does the temperature fall evenly?c Draw a trend line and predict the temperature at 20 minutes.

MATHS ASSIGNMENT

OR

EXERCISE 7.1

The exercise will certainly help your assignment