What's the Solution?
Present the range as a slider with a drag handle. The user drags the handle to set the value within the range.
When the user drags a handle to choose a value, they can easily make a selection within a range and avoid selecting an invalid value.
Sliders allow the user to easily see the entire range of valid values and the currently selected value.
Sliders help the user manipulate a value within a range. By comparison, drop down lists do not show all valid values at once, and radio buttons only provide a small click target.
Sliders allow the user to select fractional values within the allowable range.