Chapter 1.2, Problem 1.30E

a)

To determine

To identify whether the observational study or experimental study.

Answer to Problem 1.30E

This is an observational study.

Explanation of Solution

Given:

According to Louann Brizendine, author of The Female Brain, women say nearly three times as many words per day as men. Skeptical researchers devised a study to test this claim. They used electronic devices to record the talking patterns of 396 university students from Texas, Arizona, and Mexico. The device was programmed to record 30 seconds of sound every 12.5 minutes without the carrier's knowledge. What were the results? According to a published report of the study in Scientific American, "Men showed a slightly wider variability in words uttered.... But in the end, the sexes came out just about even in the daily averages: women at 16,215 words and men at 15,669

First need to understand about the experimental study and observational study:

Experimental study: Assigning people or things to groups and applying some treatment to one group, while the other group does not receive the treatment.

Observation study: In an observational study, measure or survey members of a sample without trying to affect them.

This study is an observation study. In this study, the information was recorded by device without any carrier’s knowledge. Therefore, it does not need any treatment or training.

b)

To determine

To explain why it is important for the recording device to operate without the knowledge of the carrier.

Answer to Problem 1.30E

To avoid miscommunication.

Explanation of Solution

Given:

According to Louann Brizendine, author of The Female Brain, women say nearly three times as many words per day as men. Skeptical researchers devised a study to test this claim. They used electronic devices to record the talking patterns of 396 university students from Texas, Arizona, and Mexico. The device was programmed to record 30 seconds of sound every 12.5 minutes without the carrier's knowledge. What were the results? According to a published report of the study in Scientific American, "Men showed a slightly wider variability in words uttered.... But in the end, the sexes came out just about even in the daily averages: women at 16,215 words and men at 15,669

If the carrier knew then there is possibility that they talk less which gives misleading results. To avoid the risk of wrong results, it is important to record it without carrier’s knowledge.

c)

To determine

To explain what should be the population for this study.

Answer to Problem 1.30E

The university students from Texas, Arizona, and Mexico.

Explanation of Solution

Given:

According to Louann Brizendine, author of The Female Brain, women say nearly three times as many words per day as men. Skeptical researchers devised a study to test this claim. They used electronic devices to record the talking patterns of 396 university students from Texas, Arizona, and Mexico. The device was programmed to record 30 seconds of sound every 12.5 minutes without the carrier's knowledge. What were the results? According to a published report of the study in Scientific American, "Men showed a slightly wider variability in words uttered.... But in the end, the sexes came out just about even in the daily averages: women at 16,215 words and men at 15,669

As already told in study, they used electronic devices to record the talking patterns of 396 university students from Texas, Arizona, and Mexico. Therefore, the population should be the university students from Texas, Arizona, and Mexico.