Collecting Data
Name one method of collecting data.
Survey, Poll, Questionnaire, Observation, Experiment, Research etc.
What is secondary data? provide an example.
Data collected by someone else (not you) and made available.
Example: government cencus, newspaper article, textbook etc.
What is the mode of the following data set:
1, 5, 6, 7, 6, 10, 6, 7
6
What is the population, in the cotext of statistics?
Every member of a group being studied
a) Time taken for runners to finish a race
b) Number of pets in a household
c) favourite colour of students in an art class
a) numerical
b) numerical
c) categorical
What is the range of the following data set:
5, 19, 23, 30
30 - 5 = 25
John wants to know how much time the 700 students in his school spend on their phones at night by handing out a survey.
He is deciding what sample size to use between
a) 5 b) 80 c) 400
which should he use and why?
b) 80
5 is too little
400 is too many as he would have to hand out and analyse the surveys
Jane wants to find out how active the people of her parish are. She stands outside the gym on a saturday morning and asks people exiting how often they workout a week.
Is this primary or secondary data?
What is wrong with this data collection method?
primary
biased: she is asking the people who are likely the most active as they are leaving the gym so the data will not be an accurate representation of the parish population.
What is the median in the following data set:
3, 7, 11, 16, 18
11
Give an example of how to get a random sample of people in this class.
Put names in a hat, put names in an online random name generator, assign names to numbers and use a number generator etc.
come up with two examples of numerical and two examples of categorical data.
...
13, 10, 25, 17, 5, 10
FIRST ORDER:
5, 10, 10, 13, 17, 25
(10 + 13) / 2 = 11.5
Identify two problems with this survey question AND edit the questions to make them more appropriate:
How often do you wash your hair?
a) sometimes b) a lot c) all the time
How many times a week/ month do you wash your hair?
a) 1-2 b) 3-4 c) 5-6 d) everyday
Jamie is conducting a study about the most popular lunch items available in the canteen. He asked a sample of the junior cycle students a series of questions and had his friend Joan ask his series of questions to the senior cycle students.
Is this primary or secondary data?
Primary
A small class sat a music exam. These are their results:
55, 70, 67, 88, 93, 60, 75, 75, 99, 75
What is the
a) mode
b) range
c) mean
a) 75
b) 44
c) 75.7