Math Problem Statement

sample (5).csv

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A random sample of 135 artworks created within the last three years and sold at auction has been selected to study art auction price and prior exhibition. Some of the variables recorded for each artwork are listed below.

Variable Description subid Subject ID medium type of artwork exhibWeeks the number of weeks the artwork was exhibited before the auction price sale price (in thousands) Import the data set included in the file sample.csv in Excel. To do this, you need to click on the link above and save the data file in a convenient location on your PC (in your browser, File and Save). Next open Excel, click File in the Menu, select Open and navigate to the file you previously saved – or simply double-click on it, Excel should open automatically. Use Excel and/or probTool, and appropriate hypothesis tests, to address the following research question. Assume all the test assumptions are verified.

Research question: Can linear regression be used to predict sale price (in thousands) from the number of weeks the artwork was exhibited before the auction?

Report the value of the estimated slope [use at least 4dp]: Report the value of the test statistic [use at least 2dp]: Report the p -value [use at least 3dp]: What percentage of the variation in the response variable cannot be explained by the model? Please report a number between 0 and 100 [use at least 1dp]. What is the decision of the test?

Solution

The dataset contains the following columns:

  • SubID: Subject ID (artwork identifier)
  • medium: Type of artwork (e.g., sculpture, painting)
  • exhibWeeks: Number of weeks the artwork was exhibited before auction
  • price: Sale price of the artwork (in thousands)

To answer the research question, we will perform a linear regression analysis to predict the sale price (price) based on the number of weeks the artwork was exhibited (exhibWeeks).

We'll proceed with the following steps:

  1. Perform linear regression analysis.
  2. Report the estimated slope, test statistic, p-value, and the proportion of the variation that is not explained by the model (R-squared complement).
  3. Make a decision based on the hypothesis test.

Let's perform the regression analysis.Here are the results of the linear regression analysis:

  • Estimated slope: 0.61090.6109
  • Test statistic: 10.4710.47
  • p-value: 4.512×10194.512 \times 10^{-19}
  • Percentage of variation not explained by the model: 54.8%54.8\%

Decision:

Since the p-value is extremely small (much less than 0.05), we reject the null hypothesis. This means that the number of weeks the artwork was exhibited before the auction is a significant predictor of the sale price.

Do you want more details, or do you have any questions? Here are five related questions to expand on this analysis:

  1. How do we interpret the slope of 0.6109 in the context of this problem?
  2. Can we visualize the relationship between exhibition weeks and price with a scatterplot?
  3. What would be the predicted price for an artwork exhibited for 60 weeks?
  4. How can we improve the model to explain more of the variation in sale price?
  5. What are the assumptions of linear regression, and how can we verify them?

Tip: A low R-squared suggests the need for additional variables or a non-linear model to improve prediction.

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Math Problem Analysis

Mathematical Concepts

Linear Regression
Hypothesis Testing
Correlation Analysis

Formulas

Linear regression equation: y = mx + b
Test statistic for regression slope: t = (b - 0) / SE(b)

Theorems

Least Squares Method
p-value interpretation
Coefficient of Determination (R-squared)

Suitable Grade Level

Undergraduate level (Statistics or Data Analysis)