Find the null and alternative hypotheses, Type I and II Errors and determine whether the alternative hypothesis is directional or non-directional

Question

A researcher is interested in studying whether infants can show empathy toward adults. She randomly assigns each infant to sit in a room with an adult who is pretending to cry or to sit in a room with an adult who is not showing any emotion and measures how distressed the infants become. She believes that they will become more distressed in rooms with crying adults than in rooms where the adults is not showing emotion.

Answer 1

The null hypothesis: There will be no significant difference between the babies distress.

The alternative hypothesis: The babies will be less distressed in the room with crying adults than in the room with adults showing no emotion.

The alternative hypothesis stated above is directional, because it indicated the babies will cry less. "Less" in this statement indicates the direction being predicted.

Type I Error: A false positive. Rejecting the null hypothesis, even though it is true. In this example that would mean stating there is a significant difference between the babies distress, even though there isn't one.

Type II Error: A false negative. Not rejecting the null hypothesis, even though it is false. In this example that would mean stating there is no significant difference between the babies in distress, when in fact the difference is significant.