Question

At one school, the average amount of time that spend watching television each week is The principal introduces a campaign to encourage the students to watch less television. One year later, the principal wants to perform a hypothesis test to determine whether the average amount of time spent watching television per week has decreased from the previous mean of 21.6 hours. Classify the hypothesis test as left-tailed, right-tailed, or two-tailed.

a. Two-tailed
b. Right-tailed
c. Left-tailed

Answer 1

Left Tailed

Step-by-step explanation :

Hypothesis Testing is done to test statistical significance of a mathematical assumption. Null Hypothesis is neutral hypothesis, Alternate Hypothesis shows deviation from neutral (null) hypothesis.

Null Hypothesis [H0] : Mean TV time = 21.6 hours

Alternate Hypothesis [H1] : Mean TV time < 21.6 hours

In left tailed test, alternate hypothesis states value less than null hypothesis assumed value. In right tailed test, alternate hypothesis states value greater than null hypothesis assumed value. In two tailed test, alternate hypothesis states value unequal (greater or less than) null hypothesis assumed value.

So, this case has left tailed test.