Estimating Mean and Standard Deviation

To find the _________ you add up all the numbers and then divide by how many numbers you have.

• Mean
• Median
• Mode
• Range

The mean is used in what type of distribution

• postively skewed

• negatively skewed

• symmetrical

• distributions with outliers

Answer explanation

The median is use for skewed distributions and distributions with outliers

Find the mean of these numbers:
5,11,2,12,4,2

• 4.1

• 6

• 4.5

• 4

Which measure of central tendency would best represent this data?

• Mean

• Median

• Mode

• Range

Answer explanation

Both mean and median are 4.5. Mean will vary from the median if data is skewed and /or there is outliers.

Find the best measure of centre for giraffe heights.

• 15

• 15.5

• 15.7

• 28.2

Answer explanation

The median is the best measure of centre since skewed data. Position is the 5th position from the 9 giraffes.

The mean is 15.7

All of the below sets have the same mean.

Set 1-Standard Deviation=3.1

Set 2-Standard Deviation=4.9

Set 3-Standard Deviation=1.7

Set 4-Standard Deviation=3.2

Which set of data probably has the points closest to the mean?

• 1

• 2

• 3

• 4

Answer explanation

The smallest standard deviation means that the spread of data is not great and clustered around the mean.

What does this symbol represent?

• Population Standard Deviation

• Sample Standard Deviation

• Mean Absolute Deviation

• Mean

Answer explanation

In General Maths you will only use the SAMPLE standard deviation indicated on CAS as an s_x

Use your CAS to find:

What is the sample standard deviation for the data given:

{12, 13, 29, 18, 61, 35, 21}

Assume the sample is symmetrical.

• 293.67

• 15.87

• 17.14

• 41.98

Which of the following is a measure of variability?

• mean
• median
• mode
• standard deviation