The average marks of candidates in an aptituste test was 128.5with a standard deviation of 8.2
Three scores extracted from the test are
148,102, 152, what is the average of the
extracted scores that are extreme values
fouthers (out the coutlier)

102

Step-by-step explanation:

We must calculate the value of z for each value and then compare each one and thus manage to see what is an outlier, we know that z is equal to:

z = (x - m) / sd

where x is the value to evaluate, m the mean and sd the standard deviation. Now we have to:

For x = 148:

z = (148 - 128.5) /8.2

z = 2.37

For x = 102:

z = (102 - 128.5) /8.2

z = -3.23

For x = 152:

z = (152 - 128.5) /8.2

z = 2.86

The value of this is generally between -3.09 and 3.09, so when x is 102, it goes out of range of the value of z, which means that this is the outlier.