Answer:
(A) 20
Step-by-step explanation:
From the definition of an outlier, an outlier is a value that is very much different from the rest of the values of the given data set or it can be much larger or much smaller than the other data values.
Now, the given data set is:
48, 52, 56, 64, 61, 20, 48, 51, 58, 48, 78
Since, 20 is the only value which is quite smaller from the rest of the given data values of the given data set, thus 20 is an outlier.
Hence, option A is correct.