Q. Select the outlier in the data set.4,69,75,76,79,85,89,97
List Data Set: List the data set and observe the values to identify any number that appears to be significantly different from the rest of the numbers.Data set: 4,69,75,76,79,85,89,97Observation: The number 4 seems to be much lower than all other numbers in the set.
Calculate Mean: Calculate the mean (average) of the data set.Mean = (4+69+75+76+79+85+89+97)/8Mean = (574)/8Mean = 71.75
Calculate Standard Deviation: Calculate the standard deviation of the data set. This involves several sub-steps, but for the purpose of identifying an outlier, a rough estimate or comparison of how far each number is from the mean may suffice.
Compare to Mean: Compare each number in the set to the mean to see which one is farthest away.- 4 is 67.75 units away from the mean.- 69 is 2.75 units away from the mean.- 75 is 3.25 units away from the mean.- 76 is 4.25 units away from the mean.- 79 is 7.25 units away from the mean.- 67.750 is 67.751 units away from the mean.- 67.752 is 67.753 units away from the mean.- 67.754 is 67.755 units away from the mean.Clearly, 4 is significantly farther from the mean than all other numbers.
Identify Outlier: Conclude which number is the outlier based on the comparison.The number 4 is the outlier because it is significantly farther from the mean than any other number in the set.