/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem 6 There is a theory that relative ... [FREE SOLUTION] | 91Ó°ÊÓ

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There is a theory that relative finger length depends on testosterone level. The table shows a summary of the outcomes of an observational study that one of the authors carried out to determine whether men or women were more likely to have a ring finger that appeared longer than their index finger. Identify both of the variables, and state whether they are numerical or categorical. If numerical, state whether they are continuous or discrete. $$ \begin{array}{|lcc|} \hline & \text { Men } & \text { Women } \\ \hline \text { Ring Finger Longer } & 23 & 13 \\ \hline \text { Ring Finger Not Longer } & 4 & 14 \\ \hline \end{array} $$

Short Answer

Expert verified
There are two variables in the exercise: 'Gender' and 'Finger length comparison', both of which are categorical. Identification as either continuous or discrete is not necessary as these variables are not numerical.

Step by step solution

01

Identify the Variables

In the table presented, there are two variables. The first variable is 'gender', distinguishing between men and women. The second variable is 'finger length comparison', distinguishing between people with the ring finger longer than the index finger, and people with the ring finger not longer.
02

Classify the Variables

The 'gender' variable is categorized as nominal because it divides people into different categories (men or women) with no order or priority between males and females. The 'finger length comparison' variable can also be classified as a nominal variable because it divides people into two categories - those with a longer ring finger and those who do not have a longer ring finger. This also does not suggests any order or priority between the two categories.
03

Identify if Variables are Continuous or Discrete

The question of whether a variable is continuous or discrete does not apply in this instance, as this categorization is only applicable for numerical variables. In this case, both the identified variables are categorical and thus, the terms 'discrete' and 'continuous' do not apply here.

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Key Concepts

These are the key concepts you need to understand to accurately answer the question.

Categorical Variables
When it comes to understanding data, knowing the type of variables we're dealing with is crucial. Categorical variables are one such type, and they play a pivotal role in research and analysis. They allow us to group data into categories or labels that signify some qualitative trait.

Say, for instance, we are sorting people based on a characteristic such as gender. Here, 'men' and 'women' are the categories, and since this grouping does not involve any kind of numerical value, it's a perfect example of categorical variables at work. Importantly, these don't suggest a particular order; whether you list men first or women first doesn't matter in the data - it's simply a way to categorize.

In the context of the finger length comparison study from the exercise, both 'gender' and 'finger length comparison' are categorical variables. 'Gender' divides the subjects into 'men' and 'women', whereas 'finger length comparison' categorizes them based on whether they have a longer ring finger or not.
Numerical Variables
On the flip side of categorical variables, we have numerical variables, which, as implied by the name, represent quantities and can be measured numerically. They are fundamental in datasets where the measurement or quantity of something is of interest. There are two main types of numerical variables: discrete and continuous.

Discrete Numerical Variables

Discrete variables are countable in a finite amount of time. For example, the number of students in a classroom, since you can count the students and come up with a whole number.

Continuous Numerical Variables

Continuous variables, however, can take any value within a given range. The classic example is time or weight. You can get infinitely precise with these measurements, down to microseconds or milligrams.

It's important to note that in the finger length comparison study, we are not dealing with numerical variables, as the data categorizations are based on type rather than a measurable quantity.
Finger Length Comparison Study
Considering the finger length comparison study, this kind of research falls under an observational study umbrella. In this case, the researchers are observing certain characteristics of their subjects without manipulating the study environment. The primary focus is on whether a person's ring finger is longer than their index finger, which might be associated with testosterone levels.

This study uses the categorization of subjects into 'Ring Finger Longer' or 'Ring Finger Not Longer' to compare differences between gender-based groups. The counts of individuals within each category are then compared to see if there's a noticeable trend or difference between men and women. This research can provide insights into biological attributes and possibly shed light on broader behavioral or physiological patterns.

Since the study outcomes are categorized rather than measured, the conclusions drawn from such research should be carefully interpreted, considering it does not establish cause and effect but rather indicates a potential association.
Data Classification
The process of organizing data into categories for its most effective and efficient use is known as data classification. In terms of our finger length study, classification helps us to simplify the results by categorizing the data for better visualization and analysis. This process is crucial in making the information understandable and actionable.

By classifying the data into 'Men' and 'Women', and further into subcategories based on finger length comparison, analysts can quickly identify patterns or discrepancies within the groups. It's also important to communicate the classification criteria clearly; anyone who looks at the study should easily comprehend the terms 'Ring Finger Longer' or 'Ring Finger Not Longer'.

Correctly classifying data can influence how we interpret trends, correlations, and outcomes in statistical research. It's a foundational step that can either clarify or confuse the pathway to the results, depending on the precision and appropriateness of the classification methodology adopted.

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Most popular questions from this chapter

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Refer to the description in exercise 10.71. There were 22 trials with only cockroaches (no robots) that went under one shelter. In 16 of these 22 trials, the group chose the darker shelter, and in 6 of the 22 the group chose the lighter shelter. There were 28 trials with a mixture of real cockroaches and robots that all went under one shelter. In 11 of these trials, the group chose the darker shelter, and in 17 the group chose the lighter shelter. The robot cockroaches were programmed to choose the lighter shelter (as well as preferring groups; Halloy et al. 2007 ) $$ \begin{array}{lcc} & \text { All under One Shelter } \\ \hline & \text { Cockroaches Only } & \text { Robots Also } \\ \hline \text { Darker } & 16 & 11 \\ \text { Lighter } & 6 & 17 \\ \hline \end{array} $$ Is the introduction of robot cockroaches associated with the type of shelter when the group went under one shelter? Assume cockroaches were randomly sampled from some meaningful population of cockroaches. a. Use the chi-square test to see whether the presence or absence of robots is associated with whether they went under the darker or the brighter shelter. Use a significance level of \(0.05\) b. Do Fisher's Exact Test with the data. If your software does not do Fisher's Exact Test, search the Internet for a Fisher's Exact Test calculator and use it. Report the p-value and your conclusion. c. Compare the \(\mathrm{p}\) -values for parts a and \(\mathrm{b}\). Which do you think is the more accurate procedure? The p-values that result from the two methods in this question are closer than the p-values in the previous question. Why do you think that is?

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