1. 5.1 Collecting Data Mme DiMarco

2.  Learning Goal: the focus of today’s lesson is analysing data collection and possible bias in data. We will also review mean, median and mode. Learning Goal

3.  Mean: the sum of all the numbers divided by the number of numbers. (also known as the average)  Example, calculate the mean: 7, 13, 10, 12, 14, 8, 9, 7, 11, 6 7 + 13 + 10 + 12 + 14 + 8 + 9 + 7 + 11 + 6 = 9.6 10 The mean of the number set is 9.6 Mean

4.  Median: the middle number when the numbers are arranged in order. If there are two middle numbers, we take the average of both of those numbers.  Example, calculate the median 7, 13, 10, 12, 14, 8, 9, 7, 11, 6  Step 1: arrange the numbers in order from smallest to largest  6, 7, 7, 8, 9, 10, 11, 12, 13, 14  Step 2: find the middle number  6, 7, 7, 8, 9, 10, 11, 12, 13, 14  Step 3: find the mean of the two middle numbers  9 + 10 = 9.5 2 Median

5.  Mode: the number that occurs most often  Example: calculate the mode 7, 13, 10, 12, 14, 8, 9, 7, 11, 6  The mode of this set of data is 7 Mode

6.  Range: the difference between the greatest and least numbers in a set of data  Example: calculate the range of 7, 13, 10, 12, 14, 8, 9, 7, 11, 6  Step 1: find the greatest and least numbers in the data  6 and 14  Step 2: subtract the smallest number from the largest number  14 – 6 = 8  The range of this data is 8 Range

7. 1.We will be taking a vote in class (raise your hand only once to contribute your answer) 2.What is your favourite genre of music? a)Hip hop b)Country c)Pop d)Rock e)Classical Activity

8. GenreNumber of Students Hip hop Country Pop Rock Classical Responses Do you think this survey represents PRIMARY or SECONDARY data???

9.  Primary Data: data collected by oneself, first-hand  Example, survey conducted in class by Mme DiMarco  Secondary Data: data not collected by oneself, but by other sources  Example, library books or the internet Primary vs Secondary Data

10.  It is important that the survey is conducted and data are collected in a fair way  Sometimes, the way that we ask the question may persuade someone to answer in a certain way  Bias: in data management, a misleading question that persuades those being surveyed to respond one way or another to the question Bias

11. 1)Many students are bored at the end of August, should the school year be longer?  YES _____ NO _____ 2)Some people get sick after visiting patients in a hospital. Do you think patients in a hospital should have visitation?  YES _____ NO _____ Are these question biased???

12. 1)Many students are bored at the end of August, should the school year be longer?  YES _____ NO _____  YES this question is biased. Because it includes a statement about how some students feel, this may encourage more people to say “YES”  Unbiased version  The school year is 10 months long. Should it be longer? Answer

13. 2)Some people get sick after visiting patients in a hospital. Do you think patients in a hospital should have visitation?  YES _____ NO _____  YES this question is biased as it may encourage people to say “NO”  Unbiased version  Should patients in a hospital have visitors? Answer

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