1. P=F/A and then an increase in the number of gas molecules in the same volume container increases pressure.
2. Scientifically air pressure is caused by gravity pulling down air. Air pressure is greatest at sea level.
3. The pressure will decrease with increasing altitude
4. Warm air is creating a low pressure zone, while cool air will sink creating a high pressure zone.
5. Air density plays a big role in the correlation between temperature and pressure because warmer air is less dense than cool air, and allows molecules to have more space to collide with a greater force. For the example you could say: like when the sun heats the ground, the air near the ground warms.