Any number in the interval (67.95, 68.05).
0.2
26.2
9000.0499...
4592 rounds to 4592 if you round to the nearest tenth, as tenth relates to decimal figures which aren't included in the number you gave.However, 4592 rounds to 4590 if you round to the nearest ten.
15.5
When rounding to the nearest tenth (or other fraction), you always look at the next number. Here, in 15.992 the next number is 9 (second place after decimal point), therefore it rounds up. As the next number (first place after decimal point) is also 9, this also rounds up, giving the result of 16.0. (If the number to round would be for example 15.945, the result rounded to the nearest tenth would be 15.9)
0.85 rounds to:1 to the nearest whole number/unit0.9 to the nearest tenth
0.18 rounds to:0 to the nearest whole number/unit0.2 to the nearest tenth
0.80 rounds to:1 to the nearest whole number/unit0.8 to the nearest tenth
0.11 rounds to:0 to the nearest whole number/unit0.1 to the nearest tenth
11.27 rounds to10 to the nearest ten11 to the nearest whole number/unit11.3 to the nearest tenth
8.50 rounds to10 to the nearest ten9 to the nearest whole number/unit8.5 to the nearest tenth