A3. In the group, there are eight students. Their average age is 16 years. Based on this information, we can definitely say that:
![](https://cdn.mathpix.com/cropped/2024_06_07_debf03cdc366cb9b1122g-02.jpg?height=228&width=530&top_left_y=1116&top_left_x=1388)
(A) all the students in the group are 16 years old,
(B) all the students in the group are approximately 16 years old,
(C) the majority of the students in the group are 16 years old,
(D) the sum of the ages of all the students in the group is 128 years,
(E) half of the students are younger than 16, and half are older than 16 years.
A3. The average age of eight students is $\bar{x}=\frac{x_{1}+x_{2}+\ldots+x_{8}}{8}$. From this, we get $x_{1}+x_{2}+\ldots+x_{8}=$ $8 \cdot \bar{x}$ or $8 \cdot 16=128$ years.