What is the lower bound for 67.8 rounded to one decimal place?

The lower bound for 67.8 rounded to one decimal place is 67.75.

When we talk about the lower bound of a number rounded to one decimal place, we are referring to the smallest possible value that would still round up to that number. In this case, the number is 67.8. To find the lower bound, we need to consider the range of values that would round to 67.8 when rounded to one decimal place.

A number rounds to 67.8 if it is at least 67.75 but less than 67.85. This is because any number from 67.75 up to, but not including, 67.85 will round to 67.8 when rounded to one decimal place. Therefore, the lower bound is 67.75.

To understand this better, think about how rounding works. When you round a number to one decimal place, you look at the second decimal place. If the second decimal place is 5 or higher, you round up the first decimal place. If it is 4 or lower, you keep the first decimal place the same. So, for 67.8, the smallest number that rounds up to 67.8 is 67.75, because 67.749 would round down to 67.7. This is why 67.75 is the lower bound for 67.8 rounded to one decimal place.