Targeting Grade C GCSE Mathematics Handling Data Unit 3 Interpreting Graphs

Interpret scatter diagrams TOP: Practise interpreting different charts Practice 1: What do scatter diagrams tell you? Practice 2: How do you read a line graph? Practice 3: How to compare box plots. Practice 4: What do stem and leaf diagrams tell you? TAIL Can you: Interpret scatter diagrams Interpret line graphs Compare box plots Compare stem and leaf diagrams Try a test If not you need

TOP: Make two comments for each of the following charts. Also, state which bar is the mode. 1) Saturday Sunday Monday Tuesday   The number of people who play golf are represented in this pictogram Represents 20 golfers Next

2) The bar chart shows information about the favourite drink of each student in a class. Lesson

Practice 1: Look at the following scatter diagrams Practice 1: Look at the following scatter diagrams. Do they have positive or negative correlation and what does that mean? 1a) (b) Next

2) The table lists the weights of twelve books and the number of pages in each one. On a copy of the grid, draw a scatter graph to show the information in the table. Draw a line of best fit on the graph and then describe the correlation between the number of pages in the book and their weight. Lesson

Practice 2: For the following line graph, answer the questions given. 1) Barry’s pulse rate is taken every 6 hours over 3 days. The graph shows his pulse rate in beats per minute. Write down the first pulse rate shown on the graph. Write down Barry’s highest pulse rate shown during the three days. Work out the difference between his highest and lowest pulse rates shown on 3rd May. Lesson

Practice 3: Compare the following box and whisker plots Practice 3: Compare the following box and whisker plots. Remember to compare the median (middle bar in the box) and the lower and upper quartiles (lower and upper bars of the box), as well as the start and end points of the whiskers. Remember: Quartiles represent Quarters of the data – the lower quartile is ¼ of the data and is found ¼ of the way along the data set. The upper quartile is ¾ of the data and is found ¾ of the way along the data set. The median is ½ or 2/4 of the data. Lesson

a) Find the median number of students late for school. Practice 4: For the following stem and leaf diagram, answer the questions given. Sherri recorded the number of students late for school each day for 21 days. The stem and leaf diagram shows this information. a) Find the median number of students late for school. b) Work out the range of the number of students who are late for school. Lesson

TAIL Answers? Negative correlation Joe has twelve cars for sale. The scatter diagram shows the ages and prices of the twelve cars. Describe the correlation between the age and price of these cars. Answers? Negative correlation Next

Find (i) the lower quartile (ii) the upper quartile 2) Mary recorded the heights, in centimetres, of the girls in her class. She put the heights in order. 132 144 150 152 160 162 162 167 167 170 172 177 181 182 182 Find (i) the lower quartile (ii) the upper quartile b) On a copy of the grid, draw a box plot for this data. Next for answers

Answers for Q2 Lower Quartile = 152 Upper Quartile = 177 Lesson