What is the definition of inference?

The girl walked down the street with her head hanging down; She had just lost her first soccer game. What detail from the text can tell you how the girl was feeling?

"The night was very dark. Charlie and Ted were sitting by the fire and toasting marshmallows. They had set-up their tent that afternoon. Suddenly, Ted heard a noise. Charlie heard it, too. It said, "Hoot, hoot!" It was coming from the tree over the tent. The boys threw down their marshmallows and ran all the way home."

Why did the boys run home?

When making an inference, the most important thing is...

As I walked in the door, I was amazed at the beautiful colors and smells. I knew it would be hard to decide what I would buy with my $3. The chocolate truffles looked delicious, but they were expensive. The jelly beans were not only cheaper, but so colorful! With so much to choose from, I knew I would be here a long time. Where am I?

Evidence from the text does not make for a strong argument and does not help support an inference.

The scout leader looked at the sky and muttered something under his breath. Then he looked at the map. "Let's get moving." He called to the group of tired boys. "The faster the better." Why do you think the scout leader started rushing the boys?

The scout leader looked at the sky and muttered something under his breath. Then he looked at the map. "Let's get moving." He called to the group of tired boys. "The faster the better." What evidence from the text supports your answer.

Which evidence from the text best supports the inference that the author was given alternate options for school?