Question

Meghan records the cost of bread (in $) from all the bakeries in her neighborhood as shown:
3.3, 3.8, 4.0, 4.2, 9.5, 3.5, 4.0, 4.15, 3.6, 4.3, 4.0

What is the mean cost of bread she records after ignoring the outlier?

• A. $4.0
• B. $3.88
• C. $4.39
• D. $4.83

Answer 1

The correct option is B $3.88

An outlier is a value in a data set that is either too small or too big compared to the other values of the same data set.

Arranging the data set in ascending order, we get:
3.3, 3.5, 3.6, 3.8, 4.0, 4.0, 4.0, 4.15, 4.2, 4.3, 9.5

From this, we can see that 9.5 is the outlier.

Mean (without the outlier) = $\frac{3.3+3.5+3.6+3.8+4.0+4.0+4.0+4.15+4.2+4.3}{10}$ = 3.88

Thus, the average cost of bread after ignoring the outlier is $3.88