4. (8 points) Given that the average of four numbers $a, b, c, d$ is $12.345, a>b>c>d$, then $b(\quad)$
A. Greater than 12.345
B. Less than 12.345
C. Equal to 12.345
D. Cannot be determined
4. (8 points) Given that the average of four numbers $a, b, c, d$ is $12.345, a>b>c>d$, then $b(\quad)$
A. Greater than 12.345
B. Less than 12.345
C. Equal to 12.345
D. Cannot be determined
【Solution】Since the average of the four numbers $a, b, c, d$ is $12.345, a>b>c>d$,
Therefore, $a$ must be greater than $12.345, d$ must be less than 12.345,
However, the value of $b$ cannot be determined, $b$ could be greater than 12.345, or less than 12.345, or equal to 12.345. Hence, the answer is: $D$.