Table of contents
- 1. Intro to Stats and Collecting Data55m
- 2. Describing Data with Tables and Graphs1h 55m
- 3. Describing Data Numerically1h 45m
- 4. Probability2h 16m
- 5. Binomial Distribution & Discrete Random Variables2h 33m
- 6. Normal Distribution and Continuous Random Variables1h 38m
- 7. Sampling Distributions & Confidence Intervals: Mean1h 3m
- 8. Sampling Distributions & Confidence Intervals: Proportion1h 12m
- 9. Hypothesis Testing for One Sample1h 1m
- 10. Hypothesis Testing for Two Samples2h 8m
- 11. Correlation48m
- 12. Regression1h 4m
- 13. Chi-Square Tests & Goodness of Fit1h 20m
- 14. ANOVA1h 0m
1. Intro to Stats and Collecting Data
Intro to Stats
Problem 10.1.1b
Textbook Question
Notation The author conducted an experiment in which the height of each student was measured in centimeters and those heights were matched with the same students’ scores on the first statistics test.
b. Without doing any research or calculations, estimate the value of r.

1
Understand the concept of correlation coefficient (r): It measures the strength and direction of a linear relationship between two variables. The value of r ranges from -1 to 1.
Consider the context: The problem involves matching students' heights with their scores on a statistics test. Think about whether you expect a positive, negative, or no correlation between these two variables.
Reflect on possible relationships: If taller students tend to score higher, you might expect a positive correlation. If there is no apparent relationship, the correlation might be close to zero.
Estimate the correlation: Based on your understanding of the context and the possible relationship, make an educated guess about the value of r. For example, if you think there is a slight positive relationship, you might estimate r to be around 0.2 or 0.3.
Consider variability: Remember that correlation does not imply causation, and other factors could influence the scores. Your estimate should reflect the potential variability and uncertainty in the relationship.

This video solution was recommended by our tutors as helpful for the problem above
Video duration:
3mPlay a video:
Was this helpful?
Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Correlation Coefficient (r)
The correlation coefficient, denoted as 'r', measures the strength and direction of a linear relationship between two variables. It ranges from -1 to 1, where values close to 1 indicate a strong positive correlation, values close to -1 indicate a strong negative correlation, and values around 0 suggest no linear correlation.
Recommended video:
Guided course
Correlation Coefficient
Scatter Plot
A scatter plot is a graphical representation of the relationship between two quantitative variables. Each point on the plot represents an individual data point, with one variable on the x-axis and the other on the y-axis. Analyzing the pattern of points can help estimate the correlation coefficient by visually assessing the strength and direction of the relationship.
Recommended video:
Guided course
Correlation Coefficient
Linear Relationship
A linear relationship between two variables implies that as one variable changes, the other variable tends to change in a consistent manner, either increasing or decreasing. This relationship can be represented by a straight line on a graph, and the correlation coefficient 'r' quantifies how closely the data points fit this line.
Recommended video:
Guided course
Scatterplots & Intro to Correlation
Watch next
Master Introduction to Statistics Channel with a bite sized video explanation from Patrick
Start learning