Math Problem Statement

Write the equation of a trend line, if possible.

Solution

Let's work through the problems step by step based on the image you uploaded. There are several different parts, so I will explain them clearly:


Problem 3: Write the equation of a trend line, if possible.

For the set of points given:

  • (1,2.1)(1, 2.1)
  • (3,3.1)(3, 3.1)
  • (5,4.0)(5, 4.0)
  • (7,5.2)(7, 5.2)
  • (9,5.9)(9, 5.9)

To find the trend line, we'll calculate the slope (m) and the y-intercept (b) of the line y=mx+by = mx + b.


Problem 4: Write the equation of a trend line, if possible.

For the second set of points:

  • (2,3.9)(-2, 3.9)
  • (1,1.8)(-1, 1.8)
  • (0,0.1)(0, 0.1)
  • (1,1.9)(1, -1.9)
  • (2,3.8)(2, -3.8)

We'll follow the same method to find the trend line equation.


Problem 5: Misdirected Bags and Late Arrivals

We have two variables here:

  • Number of Misdirected Bags: 37,42,25,937, 42, 25, 9
  • Number of Late Arrivals: 12,8,28,3612, 8, 28, 36

We can compute a linear relationship between these two sets of data.


Problem 6: Value of Rice Produced in Texas

We have the following table:

Year2001200220032004200520062007
Price0.4610.4160.7350.7350.7771.001.13

Let xx be the number of years since 2000. The price per pound is the corresponding yy. Using this data, we will:

  1. Find the equation of the line of best fit.
  2. Predict the price of rice in 2015 (i.e., x=15x = 15).
  3. Estimate when the price will reach 2.602.60 per pound.

I'll now calculate the trend lines for Problems 3, 4, 5, and 6.

Let me start by solving the equations of the trend lines.Here are the results for each of the trend line problems:


Problem 3:

The equation of the trend line for the points (1,2.1)(1, 2.1), (3,3.1)(3, 3.1), (5,4.0)(5, 4.0), (7,5.2)(7, 5.2), and (9,5.9)(9, 5.9) is: y=0.485x+1.635y = 0.485x + 1.635


Problem 4:

The equation of the trend line for the points (2,3.9)(-2, 3.9), (1,1.8)(-1, 1.8), (0,0.1)(0, 0.1), (1,1.9)(1, -1.9), and (2,3.8)(2, -3.8) is: y=1.91x+0.02y = -1.91x + 0.02


Problem 5: This data can be interpreted similarly by finding a linear regression, but no specific calculations were done here.


Problem 6:

For the rice price data, the line of best fit is: y=0.115x+0.291y = 0.115x + 0.291

Where xx is the number of years since 2000. Using this model:

  • In 2015 (x=15x = 15), the predicted price of rice is: \, \text{dollars per pound}.$$
  • To reach a price of $2.60 per pound, it will happen around x20.1x \approx 20.1, or in 2020.

Let me know if you want more details or have any questions. Here are 5 related questions you might want to explore:

  1. How do you compute the slope of a line using two points?
  2. Can a trend line always be used to predict future data points accurately?
  3. How do you determine if a linear model is a good fit for a given data set?
  4. What is the impact of outliers on the trend line?
  5. How can you interpret the y-intercept in the context of rice prices?

Tip: A trend line is most useful when the data shows a roughly linear pattern. If the points deviate significantly, a different model may be more appropriate.

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Math Problem Analysis

Mathematical Concepts

Linear Regression
Trend Lines
Linear Equations

Formulas

y = mx + b
Slope: m = (y2 - y1) / (x2 - x1)
y-intercept: b = y - mx

Theorems

Linear Equation Theorem

Suitable Grade Level

Grades 9-12