Answer:
Option C (The mean would decrease).
Step-by-step explanation:
In this question, there are 16 observations and their mean is 80. There is an outlier which has the value 91. This means that the outlier is on the greater side of the mean. The formula for mean is:
Mean = Sum of observations/Number of Observations.
Sum of observations can be calculated by substituting the values in the above formula.
80 = Sum/16.
Sum = 80*16 = 1280.
Subtracting 91 from the total sum will give the sum of rest of the 15 non-outlier values. Therefore 1280 - 91 = 1189.
Calculating the mean of the 15 values:
Mean = 1189/15 = 79.267 (correct to 3 decimal places).
It can be seen that removing the outlier decreases the mean. Therefore C is the correct answer. The information regarding the median cannot be determined since actual values are not present, which are required to calculate the median. Therefore, C is the correct choice!!!
