Starter Find the medians of these sets of data: 1, 6, 5, 3, 8, 5, 4 11, 15, 17, 12, 19 99, 95, 96, 95, 95 72, 78, 54, 54, 64, 66 = 5 = 15 = 95 = 65

0 < t ≤ 5 5 < t ≤ 10 10 < t ≤ 15 15 < t ≤ 20 The table below shows the number of minutes students were late for their fun Maths lesson in the Autumn Term. (a) Draw a Cumulative Frequency Diagram of the data (b) Use it to find the Median, Lower Quartile, Upper Quartile, and Inter Quartile Range (c) Draw a Box-Plot assuming a minimum time of 0 minutes and a maximum of 25 minutes Time t (mins) Number of Students Cumulative Frequency 0 < t ≤ 5 10 5 < t ≤ 10 16 10 < t ≤ 15 30 15 < t ≤ 20 22 20 < t ≤ 25 2 10 26 56 78 80

80 x x Cum freq 60 x 40 x 20 x 5 10 15 20 25 t mins

x 80 x Cum freq 60 x Median = Middle Value 40 QUARTILES Lower Quartile = ¼ way Upper Quartile = ¾ way x 20 Interquartile Range = 15½ - 8½ = 7 mins x 8½ 12½ 15½ 5 10 15 20 25 t mins

Inter quartile range = 15 ½ - 8 ½ = 7 mins The table below shows the number of minutes students were late for their fun Maths lesson in the Autumn Term. (a) Draw a Cumulative Frequency Diagram of the data (b) Use it to find the Median, Lower Quartile, Upper Quartile, and Inter Quartile Range (c) Draw a Box-Plot assuming a minimum time of 0 minutes and a maximum of 25 minutes Median = 12 ½ mins Lower quartile = 8 ½ mins Upper quartile = 15 ½ mins Inter quartile range = 15 ½ - 8 ½ = 7 mins

12 ½ 25 8 ½ 15 ½ Minimum value Median Maximum value Lower Quartile 12 ½ 25 Minimum value 8 ½ Median 15 ½ Maximum value Lower Quartile Upper Quartile 5 10 15 20 25 t mins

What are the differences? Spring term Autumn term What are the similarities?