Question

For each of the following examples, state the null hypothesis and the research hypothesis, in both words and symbolic notation:

a) Musician David Teie worked with animal researchers to develop music specifically for cats—music that a typical cat might find relaxing (Stanford, 2015). Imagine that you decided to study whether cat-specific music led to decreased heart rate in feline listeners. Use a one-tailed hypothesis.
b) The National Sleep Foundation encourages U.S. high schools to start later in the morning to improve teenagers’ sleep and school performance (2015). Imagine you decide to conduct a study to see if teens who get to sleep an hour later have different grades than those who don’t.
c) Smartphones are everywhere, and we are now available to our friends and families almost all of the time. Does this translate into a change in the closeness of our long-distance relationships?

Answer 1

The null hypothesis is that cat-specific music does not lead to decreased heart rate in cats, while the research hypothesis is that it does.

Step-by-step explanation:

The null hypothesis for the first example, where cat-specific music is being studied for its effect on cat heart rate, would be:

Null hypothesis: Cat-specific music does not lead to decreased heart rate in feline listeners.

The research hypothesis, in words, would be:

Research hypothesis: Cat-specific music leads to decreased heart rate in feline listeners.

In symbolic notation:

H0: μ ≤ 0 (mean heart rate without cat-specific music is less than or equal to 0)

Ha: μ > 0 (mean heart rate without cat-specific music is greater than 0)

This is a one-tailed test because we are only interested in whether cat-specific music leads to a decrease in heart rate, not an increase or any change in a different direction.