
Concept explainers
Categorical or quantitative? Identify each of the following variables as categorical or quantitative.
- a. Number of children in family
- b. Amount of time in football game before first points scored
- c. College major (English, history, chemistry,…)
- d. Type of music (rock, jazz, classical, folk, other)
a.

Identify whether the variable is categorical or quantitative variable.
Answer to Problem 90CP
The variable number of children in family is quantitative variable.
Explanation of Solution
The given variable is that “number of children in family”.
Categorical variables and quantitative variables:
The variables are classified as categorical and quantitative variable. Quantitative variables are those variables that take numerical values while categorical variables do not take numerical values. Therefore, categorical variables are those in which observations belong to one set of categories and quantitative are those variables in which observation are numerical values.
The number of children in family can take values 0, 1, 2… etc. That is, the variable “number of pets in family” can take numerical values. Therefore, number of children in family is quantitative variable.
b.

Identify whether the variable is categorical or quantitative variable.
Answer to Problem 90CP
The variable amount of time in football game before first point is quantitative variable.
Explanation of Solution
The given variable is that “amount of time in football game before first point”.
The amount of time in football game before first point can take numerical values. Therefore, amount of time in football game before first point is quantitative variable.
c.

Identify whether the variable is categorical or quantitative variable.
Answer to Problem 90CP
The variable college major is categorical variable.
Explanation of Solution
The given variable is that “college major”.
The variable college major includes name of the subjects such as English, history, chemistry, etc. That is, the variable cannot take numerical values these are different subjects. Therefore, the variable college major is categorical variable.
d.

Identify whether the variable is categorical or quantitative variable.
Answer to Problem 90CP
The variable type of music is categorical variable.
Explanation of Solution
The given variable is that “type of music”.
The type of music is rock, jazz, classical, folk, and others. That is, the variable types of music do not take numerical values. Therefore, the variable type of music is categorical variable.
Want to see more full solutions like this?
Chapter 2 Solutions
Statistics: The Art and Science of Learning From Data, Books a la Carte Edition (4th Edition)
- 4. Linear Regression - Model Assumptions and Interpretation A real estate analyst is studying how house prices (Y) are related to house size in square feet (X). A simple linear regression model is proposed: The analyst fits the model and obtains: • Ŷ50,000+150X YBoB₁X + € • R² = 0.76 • Residuals show a fan-shaped pattern when plotted against fitted values. Questions: a) Interpret the slope coefficient in context. b) Explain what the R² value tells us about the model's performance. c) Based on the residual pattern, what regression assumption is likely violated? What might be the consequence? d) Suggest at least two remedies to improve the model, based on the residual analysis.arrow_forward5. Probability Distributions – Continuous Random Variables A factory machine produces metal rods whose lengths (in cm) follow a continuous uniform distribution on the interval [98, 102]. Questions: a) Define the probability density function (PDF) of the rod length.b) Calculate the probability that a randomly selected rod is shorter than 99 cm.c) Determine the expected value and variance of rod lengths.d) If a sample of 25 rods is selected, what is the probability that their average length is between 99.5 cm and 100.5 cm? Justify your answer using the appropriate distribution.arrow_forward2. Hypothesis Testing - Two Sample Means A nutritionist is investigating the effect of two different diet programs, A and B, on weight loss. Two independent samples of adults were randomly assigned to each diet for 12 weeks. The weight losses (in kg) are normally distributed. Sample A: n = 35, 4.8, s = 1.2 Sample B: n=40, 4.3, 8 = 1.0 Questions: a) State the null and alternative hypotheses to test whether there is a significant difference in mean weight loss between the two diet programs. b) Perform a hypothesis test at the 5% significance level and interpret the result. c) Compute a 95% confidence interval for the difference in means and interpret it. d) Discuss assumptions of this test and explain how violations of these assumptions could impact the results.arrow_forward
- 1. Sampling Distribution and the Central Limit Theorem A company produces batteries with a mean lifetime of 300 hours and a standard deviation of 50 hours. The lifetimes are not normally distributed—they are right-skewed due to some batteries lasting unusually long. Suppose a quality control analyst selects a random sample of 64 batteries from a large production batch. Questions: a) Explain whether the distribution of sample means will be approximately normal. Justify your answer using the Central Limit Theorem. b) Compute the mean and standard deviation of the sampling distribution of the sample mean. c) What is the probability that the sample mean lifetime of the 64 batteries exceeds 310 hours? d) Discuss how the sample size affects the shape and variability of the sampling distribution.arrow_forwardA biologist is investigating the effect of potential plant hormones by treating 20 stem segments. At the end of the observation period he computes the following length averages: Compound X = 1.18 Compound Y = 1.17 Based on these mean values he concludes that there are no treatment differences. 1) Are you satisfied with his conclusion? Why or why not? 2) If he asked you for help in analyzing these data, what statistical method would you suggest that he use to come to a meaningful conclusion about his data and why? 3) Are there any other questions you would ask him regarding his experiment, data collection, and analysis methods?arrow_forwardBusinessarrow_forward
- What is the solution and answer to question?arrow_forwardTo: [Boss's Name] From: Nathaniel D Sain Date: 4/5/2025 Subject: Decision Analysis for Business Scenario Introduction to the Business Scenario Our delivery services business has been experiencing steady growth, leading to an increased demand for faster and more efficient deliveries. To meet this demand, we must decide on the best strategy to expand our fleet. The three possible alternatives under consideration are purchasing new delivery vehicles, leasing vehicles, or partnering with third-party drivers. The decision must account for various external factors, including fuel price fluctuations, demand stability, and competition growth, which we categorize as the states of nature. Each alternative presents unique advantages and challenges, and our goal is to select the most viable option using a structured decision-making approach. Alternatives and States of Nature The three alternatives for fleet expansion were chosen based on their cost implications, operational efficiency, and…arrow_forwardBusinessarrow_forward
- Why researchers are interested in describing measures of the center and measures of variation of a data set?arrow_forwardWHAT IS THE SOLUTION?arrow_forwardThe following ordered data list shows the data speeds for cell phones used by a telephone company at an airport: A. Calculate the Measures of Central Tendency from the ungrouped data list. B. Group the data in an appropriate frequency table. C. Calculate the Measures of Central Tendency using the table in point B. 0.8 1.4 1.8 1.9 3.2 3.6 4.5 4.5 4.6 6.2 6.5 7.7 7.9 9.9 10.2 10.3 10.9 11.1 11.1 11.6 11.8 12.0 13.1 13.5 13.7 14.1 14.2 14.7 15.0 15.1 15.5 15.8 16.0 17.5 18.2 20.2 21.1 21.5 22.2 22.4 23.1 24.5 25.7 28.5 34.6 38.5 43.0 55.6 71.3 77.8arrow_forward
- Holt Mcdougal Larson Pre-algebra: Student Edition...AlgebraISBN:9780547587776Author:HOLT MCDOUGALPublisher:HOLT MCDOUGALGlencoe Algebra 1, Student Edition, 9780079039897...AlgebraISBN:9780079039897Author:CarterPublisher:McGraw HillBig Ideas Math A Bridge To Success Algebra 1: Stu...AlgebraISBN:9781680331141Author:HOUGHTON MIFFLIN HARCOURTPublisher:Houghton Mifflin Harcourt


