Objectives (5  7 minutes)
 To provide students with a basic understanding of what a line of best fit is in a scatter plot and its role in estimating trends and making predictions.
 To develop students' skills in drawing and interpreting lines of best fit in scatter plots.
 To enhance students' ability to estimate the points that are not in the scatter plot based on the line of best fit.
Secondary Objectives:
 To encourage students to work collaboratively in small groups, promoting teamwork and communication skills.
 To foster students' critical thinking by engaging them in handson activities and problemsolving tasks related to the main topic.
 To instill an appreciation for the practical applications of lines of best fit in realworld scenarios.
Introduction (10  12 minutes)

The teacher begins the lesson by reminding the students of their previous knowledge of scatter plots in the context of data representation. They can briefly review the concept of dependent and independent variables, and how they are plotted on the x and yaxes respectively. This will serve as a foundation for the new topic.

The teacher then presents two problem situations to the students. The first situation could be about a car's fuel efficiency, with the number of passengers as the independent variable and the distance traveled as the dependent variable. The second situation could be about a student's study time and their test scores, with the former as the independent variable and the latter as the dependent variable. The teacher asks the students to think about how they can represent these situations on a scatter plot.

To introduce the topic of estimating lines of best fit, the teacher can present a realworld application. For example, they can talk about how marketers use data to estimate trends and make predictions about consumer behavior. The teacher can explain that a line of best fit helps them to see a trend in the data and make predictions about future behavior.

To grab the students' attention, the teacher can share two interesting facts or stories related to lines of best fit. For instance, they can tell the story of how a Swedish chemist, Torbern Bergman, first used the method of least squares, the basis for estimating lines of best fit, in the 18th century. The teacher can also share a fun fact about how lines of best fit are used in sports analytics to predict player performance and make strategic decisions during games.

After sharing these stories, the teacher can ask the students to think of other situations where they might encounter lines of best fit in real life. This will not only engage the students in the lesson, but also help them to see the relevance of the topic beyond the classroom.
Development (20  25 minutes)
Activity 1: The Best Fit Bodybuilders
In this activity, students will work in small groups to draw a line of best fit on a scatter plot that represents data about the height and weight of professional bodybuilders. They will then use this line to estimate the weight of a bodybuilder given his height.

The teacher provides each group with a large sheet of graph paper and a set of data cards with information about the height and weight of different professional bodybuilders. The data should spread across the graph paper, but not so much that it is impossible to draw a line of best fit.

The teacher instructs the students to plot the data on the graph paper, with height on the xaxis and weight on the yaxis. They should make sure to label the axes and the data points properly.

Once the data is plotted, the teacher explains how to draw a line of best fit. They should note that the line should pass through the middle of the scatter plot, touching as many data points as possible, while minimizing the total distance from each point to the line.

The students then draw a line of best fit on their graph. The teacher circulates the room, providing guidance and feedback as needed.

After the line is drawn, the teacher selects a bodybuilder that is not included in the original data and asks each group to estimate his weight based on their line of best fit. The students record their estimates.

Finally, the teacher reveals the actual weight of the bodybuilder and the groups compare their estimates with the actual value. This allows for a discussion on the accuracy of the line of best fit in estimating values.
Activity 2: Trend Predictions in Fashion
In this activity, students will work in the same groups to create a scatter plot based on data about the popularity of different fashion trends over time. They will then draw a line of best fit and use it to predict the popularity of a trend in the future.

The teacher provides each group with a different set of data about the popularity of various fashion trends over the years. The data should show some fluctuations, but a discernible trend should be present.

The students are instructed to plot the data on a new sheet of graph paper, with time on the xaxis and trend popularity on the yaxis. Again, the axes and data points should be labeled properly.

The teacher explains how to draw a line of best fit in this context, emphasizing how it can help predict the popularity of a trend in the future. They also remind the students that the line should minimize the total distance from each point.

The students then draw a line of best fit on their graph, using it to predict the popularity of one of the trends in the future. They record their predictions and the reasoning behind them.

The teacher then shares the actual popularity data for the subsequent years, allowing the groups to compare their predictions with the actual values. This leads to a discussion on the accuracy and limitations of using a line of best fit to make predictions.
During both activities, the teacher walks around the room, providing support, answering questions, and facilitating group discussions. At the end of the activities, the teacher should facilitate a classwide discussion about the results, ensuring that the students understand the main concepts and can relate them to realworld situations.
Feedback (8  10 minutes)

The teacher initiates a group discussion, where each group is given a chance to share their solutions and the conclusions they drew from the two activities. This allows for comparisons and discussions on the different approaches used by the groups and the results obtained. (3  4 minutes)

The teacher then facilitates a reflective session, where they ask the students to connect the handson activities with the theoretical concepts. For example, they can ask the students how the line of best fit helps to estimate trends and make predictions, and how this was demonstrated in the activities. The teacher can also ask the students to share their thoughts on the limitations of using a line of best fit for predictions, as shown in the second activity. (2  3 minutes)

The teacher then encourages the students to reflect on their learning by asking them to write down their answers to the following questions:
 What was the most important concept you learned today?
 What questions do you still have about estimating lines of best fit?
 How can you apply the concept of lines of best fit in real life? (2  3 minutes)

The teacher collects the students' written reflections and uses them to assess the students' understanding of the topic and to plan for future lessons, addressing any areas of confusion or interest raised by the students. The teacher should also provide feedback on the students' work during the activities, highlighting the strengths and areas for improvement. (1 minute)

Finally, the teacher concludes the lesson by summarizing the main points and reminding the students about the importance of estimating lines of best fit in analyzing trends and making predictions. The teacher can also preview the next lesson, which could focus on more advanced topics related to scatter plots, such as outliers and the correlation coefficient. (1 minute)
During this feedback stage, the teacher should create a supportive and nonjudgmental environment, encouraging all students to participate and share their thoughts. The teacher should also be prepared to provide additional clarification or examples as needed, ensuring that all students have a clear understanding of the topic.
Conclusion (5  7 minutes)

The teacher begins the conclusion by summarizing the main content of the lesson. They remind the students that a line of best fit is a straight line that comes closest to the points on a scatter plot, and it is used to estimate the trend in the data and make predictions about future values. The teacher reiterates the process of drawing a line of best fit and the importance of minimizing the total distance from each point to the line. (1  2 minutes)

The teacher then explains how the lesson connected theory, practice, and applications. They remind the students that the handson activities allowed them to apply the theoretical knowledge to practical situations. The teacher also emphasizes the realworld applications discussed in the lesson, such as estimating a bodybuilder's weight or predicting the popularity of a fashion trend. They point out that these applications demonstrate the relevance and importance of the topic in everyday life. (1  2 minutes)

The teacher then suggests additional materials to complement the students' understanding of the topic. They can recommend online resources such as interactive scatter plot tools, video tutorials on drawing lines of best fit, and practice exercises. The teacher can also suggest related topics for further exploration, such as outliers in scatter plots and the correlation coefficient. (1 minute)

Finally, the teacher underscores the importance of the topic for everyday life. They explain that understanding lines of best fit can help in various realworld scenarios, from predicting consumer behavior for marketers to estimating a car's fuel efficiency based on the number of passengers. The teacher also encourages the students to be aware of the use of lines of best fit in news and media, and to critically evaluate the predictions made based on these lines. (1  2 minutes)

The teacher concludes the lesson by expressing their expectation that the students have gained a solid understanding of lines of best fit, and encouraging them to continue applying and exploring this concept in their future studies. (1 minute)