Download Test Yourself – Basic Statistics

LDU Maths, Statistics and Numeracy Support
Test Yourself – Basic Statistics
1) What is the mean of the following numbers?
1, 2, 3, 5, 5, 5, 7, 9, 11, 12
2) What is the median of the following numbers?
1, 2, 3, 5, 5, 5, 7, 9, 11, 12
3) What is the mode for the following numbers?
1, 2, 3, 5, 5, 5, 7, 9, 11, 12
4) What is the range of the following numbers?
1, 2, 3, 5, 5, 5, 7, 9, 11, 12
5) The set of numbers in questions 1 – 3 has been changed to include
an outlier: 1, 2, 3, 5, 5, 5, 7, 9, 11, 60. Which of the following will
be affected by this change: the mean, median or the mode?
6) If the mean, median and mode for a data set are different then the
data will be skewed, true or false?
7) A standard deviation (s) measures the variation in data sets, true
or false?
8) The coefficient of variation is used to compare the variation in
different data sets, true or false?
9) Letters from the Greek alphabet are used to denote sample
statistics rather than population statistics, true or false?
LDU Maths, Statistics and Numeracy Support
Test Yourself – Basic Statistics
ANSWERS
1) (1+2+ 3+ 5+ 5+ 5+ 7+ 9+ 11+ 12) ÷ 10 = 6
The mean of a sample is called x bar ( and the notation is
2) 1, 2, 3, 5, 5, 5, 7, 9, 11, 12
The median (middle number when data is arranged in order) is 5. If there are
2 middle numbers you can take the average of them to find the median.
3) 1, 2, 3, 5, 5, 5, 7, 9, 11, 12 The mode (most frequently occurring
number) is 5.
4) 1, 2, 3, 5, 5, 5, 7, 9, 11, 12
The range (or spread) of data is found by subtracting the lowest from the
highest 12 – 1 = 11 (the data points are no more than 11 apart).
5)
6)
7)
The mean will be affected by outliers. Calculate the mean, median
and mode and compare your answers to those of questions 1-3
TRUE. If the mode and median are smaller than the mean then the data
is positively skewed. If the mode and median are greater than the
mean then the data is negatively skewed.
TRUE. The larger the standard deviation the more varied (spread apart)
is the data set.
8)
TRUE. The formula is
9)
100
FALSE. The Greek alphabet is used for population parameters such as
mean μ (mu) and standard deviation σ (sigma).