Answer:
The value of the missing digit is 6.
Step-by-step explanation:
When a number is divisible by 9, the sum of the digits must be 9 or a multiple of 9.
Given digits = 6785∆4
the sum of the digits = 30 + ∆
30 + ∆ = 36
∆ = 36 - 30
∆ = 6
Thus, the value of the missing digit is 6.
