**Investigate the effect of individual data values , including outliers, on the mean and median (ACMSP207)**

**Investigate the effect of individual data values , including outliers, on the mean and median (ACMSP207)**

**LO: To identify the effects of an outlier on data.**

**Know:**

- What an outlier is
- How to calculate the mean of a set of data
- How to calculate the median of a set of data
- How to calculate the mode of a set of data
- How to calculate the range of a set of data

**Understand:**

- That outliers can sometimes cause issues to the interpretation of collected data and that the removal of outliers helps us to get a more accurate representation of data.

**Do:**

- I can identify the effect of outliers to a set of collected data.

**Outliers**

### Outliers is data which don’t fit the general trend. They tend to be away from where the majority of the data lies.

**Effect of Outliers on Data**

### Outliers can skew data especially the mean and median from a data set.

### If you look at the effects below, without outliers the mean of the data set was 3. If you have outlying data with a value of 10, it changed the mean to 4. In this case the mean didn’t shift that much.

### But if you look in the second scenario, you have the same data set but with 300 as an outlier. The mean shifted from 5.45 to 30, which is a huge shift.

### So 1 outlying value can have significant changes to the mean (average) of a data set.

**Outlier Videos**

**Outlier Videos**