Category 1
What is a population is statistics?
The whole group being studied.
What type of data is "The mass of each shell in a collection of sea shells"
Numerical Continuous
What is Bias in Data?
A tendency which causes a difference in the results of a survey and the true facts.
Which is more affected by outliers: mean or median?
The mean
Five numbers have mean 10. What is their total?
50
What type of data is "The results of a survey asking people to rate a TV program as good, satisfactory or poor"
Categorical Ordinal
What is numerical discrete data?
Data that can be counted and has a limited amount of values
What is a Bi-Modal Set of Data?
A set of data that has 2 peaks.
What is the mean?
Add values and divide by how many values there are.
6 and 7
What are the three sampling methods?
Simple random, Systematic and Stratified.
What is an outlier?
A value in the data that is far bigger or smaller than the others.
Find the median of 2, 6, 9, 4, 1, 7
5
What is the median?
The middle value in ordered data.
Find the mean of 8, 12, and 16.
12
What is numerical continuous data?
Data that can be measured - can take on any value
What is categorical ordinal data?
Categorical data that can be sorted into groups or categories
Find the mean of 4,6 and 10.
6.67
Test scores: 60, 65, 70, 95.
Which average best represents the group?
The median
What type of data is "The number of computers in a household"
Numerical Discrete
A data set’s mean is 18. If a very large value is added, what happens to the mean?
It increases.
A survey only asks students in the top maths class about homework difficulty. Explain why this is biased.
It doesn’t represent all students’ abilities or opinions.
Five numbers have a mean of 14. What is the total of the five numbers?
70
Why is the median often better than the mean when salaries are compared?
Because extreme high salaries (outliers) affect the mean but not the median.
Five numbers have mean 12. One large number is removed and the mean becomes 10. Was the removed number above or below 12?
Above 12, because removing a large value lowers the mean.