/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem 26 The data given in Example \(5.5\... [FREE SOLUTION] | 91Ó°ÊÓ

91Ó°ÊÓ

The data given in Example \(5.5\) on \(x=\) call-to-shock time (in minutes) and \(y=\) survival rate (percent) were used to compute the equation of the least- squares line, which was $$ \hat{y}=101.36-9.30 x $$ The newspaper article "FDA OKs Use of Home Defibrillators" (San Luis Obispo Tribune, November 13,2002 ) reported that "every minute spent waiting for paramedics to arrive with a defibrillator lowers the chance of survival by 10 percent." Is this statement consistent with the given least-squares line? Explain.

Short Answer

Expert verified
Yes, the statement is approximately consistent with the given least square line. While the line suggests a survival rate decrease of 9.3% per minute, the article indicates a 10% decrease per minute. The figures are similar, hence approximate consistency can be inferred.

Step by step solution

01

Understand the Least-Squares Line

The least-squares line \(\hat{y}=101.36 - 9.30x\) acts as a predictive model for survival rate based on the call-to-shock time. The coefficient of \(x\) (-9.30) is significant because it denotes the rate of decrease in survival percentage for each additional minute the defibrillator is delayed.
02

Examine the Newspaper Statement

According to the statement in the newspaper article, every minute delay in the arrival of defibrillators lowers survival rate by 10%. It implies a decrease of 10 units in survival rate per minute, which corresponds to an assumed linear model with a slope of -10.
03

Compare the Two Statements

The two statements can now be compared. The newspaper statement suggests a decrease in survival rate at a rate of 10% per minute, while the computed least squares line suggests a decrease at a rate of 9.30% per minute. Although these values are not exactly the same, they are very close, suggesting an approximate agreement between the two.

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with 91Ó°ÊÓ!

Key Concepts

These are the key concepts you need to understand to accurately answer the question.

Predictive Model
A predictive model is a tool that helps project future outcomes based on existing data. In the context of the least-squares regression, the formula derived, which in this case is \( \hat{y} = 101.36 - 9.30x \), serves as our predictive model.
This equation forecasts the survival rate based on the time it takes for assistance to arrive at an emergency scene, specifically with a defibrillator.
The \(y\)-intercept, 101.36, represents the predicted survival rate when the wait time is zero minutes. Meanwhile, the slope coefficient, -9.30, informs us how much the survival rate decreases with each additional minute of delay.
  • The slope indicates negative correlation — as the wait time increases, the survival rate decreases.
  • This model allows us to predict survival rates for any given call-to-shock time, though always consider its limitations and the context of its application.
By understanding the significance of each part of the equation, we can accurately interpret and apply the predictive model to make informed decisions.
Survival Rate Analysis
Survival rate analysis involves examining various factors that can influence outcomes, in this case, how delay affects survival rates in emergency situations. The given least-squares equation provides insights into this by calculating the impact of response times on survival outcomes.

Particularly, this model shows the survival rate decreases by approximately 9.30% for each minute that paramedics are delayed. Such analysis is crucial for emergency management teams to improve their response times and equipment, thereby maximizing survival outcomes.
  • Identifying key variables, such as time to defibrillator use, helps direct resources effectively.
  • Each percentage point decrease can have critical implications; hence, even a minimal reduction in response time can save lives.
This analysis helps emphasize the importance of quick response times and continuous efforts to reduce them.
Linear Relationship
A linear relationship refers to a consistently proportional connection between two variables. In this exercise, we are exploring the linear relationship between the call-to-shock time and the survival rate, which the least-squares line models.
The equation \( \hat{y} = 101.36 - 9.30x \) signifies that for any given linear relationship, any increase in \(x\) (call-to-shock time) leads to a consistent change in \(y\) (survival rate).
The direct interpretation is that as the minutes increase, the survival rate predictably decreases.
  • This ensures a straightforward expectation — every additional minute waiting results in a consistent decrease.
  • A linear model is simple and easy to understand, making it useful for quick predictions and insights.
However, it's also important to recognize that real-world data can sometimes reflect more complexity, making it necessary to consider additional factors beyond this basic linear relationship.

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

'The article "Reduction in Soluble Protein and Chlorophyll Contents in a Few Plants as Indicators of Automobile Exhaust Pollution" (International Journal of Environmental Studies [1983]: \(239-244\) ) reported the following data on \(x=\) distance from a highway (in meters) and \(y=\) lead content of soil at that distance (in parts per million): a. Use a statistical computer package to construct scatterplots of \(y\) versus \(x, y\) versus \(\log (x), \log (y)\) versus \(\log (x)\) and \(\frac{1}{y}\) versus \(\frac{1}{x}\). b. Which transformation considered in Part (a) does the best job of producing an approximately linear relationship? Use the selected transformation to predict lead content when distance is \(25 \mathrm{~m}\).

A sample of automobiles traversing a certain stretch of highway is selected. Each one travels at roughly a constant rate of speed, although speed does vary from auto to auto. Let \(x=\) speed and \(y=\) time needed to traverse this segment of highway. Would the sample correlation coefficient be closest to \(.9, .3,-.3\), or \(-.9 ?\) Explain.

The accompanying data represent \(x=\) the amount of catalyst added to accelerate a chemical reaction and \(y=\) the resulting reaction time: $$ \begin{array}{rrrrrr} x & 1 & 2 & 3 & 4 & 5 \\ y & 49 & 46 & 41 & 34 & 25 \end{array} $$ a. Calculate \(r\). Does the value of \(r\) suggest a strong linear relationship? b. Construct a scatterplot. From the plot, does the word linear really provide the most effective description of the relationship between \(x\) and \(y\) ? Explain.

Is the following statement correct? Explain why or why not. A correlation coefficient of 0 implies that no relationship exists between the two variables under study.

The article "Cost-Effectiveness in Public Education" (Chance [1995]: \(38-41\) ) reported that for a regression of \(y=\) average SAT score on \(x=\) expenditure per pupil, based on data from \(n=44\) New Jersey school districts, \(a=766, b=0.015, r^{2}=.160\), and \(s_{e}=53.7\) a. One observation in the sample was \((9900,893)\). What average SAT score would you predict for this district, and what is the corresponding residual? b. Interpret the value of \(s_{e}\). c. How effectively do you think the least-squares line summarizes the relationship between \(x\) and \(y ?\) Explain your reasoning.

See all solutions

Recommended explanations on Math Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.