What is Wrong with These Statements?

1. The air temperature was 33 F in the night and 66 F in the day. So in the day it was twice as warm as in the night.

2. The United Nations Organization declared that the world's six-billionth inhabitant was born on October 12, 1999 in Bosnia.

True or False?

3. When we are selecting the class width, we may, for more convenience, round it off to the nearest whole number.

4. If you add 1 to each score in a data set, the mean for this set will also increase by 1.