if a data set has mean 70, and standard deviation 5, is 80 asuspect outliner/
No.
To determine if 80 is a suspect outlier in a data set with a mean of 70 and a standard deviation of 5, we can use the concept of z-scores.
A z-score measures the number of standard deviations an observation is away from the mean. It helps us identify how unusual or extreme a particular data point is in comparison to the rest of the data set.
To calculate the z-score of a value, you can use the formula:
Z = (X - μ) / σ
Where:
- X is the value you want to calculate the z-score for (in this case, 80).
- μ is the mean of the data set (in this case, 70).
- σ is the standard deviation of the data set (in this case, 5).
Substituting the values into the formula, we have:
Z = (80 - 70) / 5
Z = 10 / 5
Z = 2
The calculated z-score for the value 80 is 2.
Now, to determine if 80 is a suspect outlier, we need to set a threshold or cutoff point. A common convention is to consider values as outliers if their z-scores are greater than 2 or less than -2.
In this case, the z-score of 2 for 80 indicates that it is 2 standard deviations above the mean. Given that it is not greater than the threshold of 2, we can conclude that 80 is not a suspect outlier in this data set.