Most states conduct regular safety checks of bridges, giving a structural deficiency score on various scales....

  

 

  

Transcribed Image Text:

Most states conduct regular safety checks of bridges, giving a structural deficiency score on various scales. The New York State Department of Transportation uses a scale that runs from 1 to 7, with a score of 5 or less indicating "deficient. Many factors contribute to the deterioration of a bridge, including amount of traffic, material used in the bridge, weather, and bridge design. New York has more than 17,000 bridges. The scatterplot above shows the relationship between the age and safety score of the 194 bridges of Tompkins County. (a) Describe the general relationship/trend between the age and safety score of the bridges of Tompkins County. Intuitively why does the this trend make sense? (b) Given the above data points from the 194 bridge observations, we form the linear least squares model estimate for predicting the safety score of a bridge from its age. Doing so we obtain the following equation of the regression line: safety score=bo + bage where bo = 6.30 Sketch this "best fit" line through the data above and use this model to predict the safety score of a bridge which is 100 years old. and by=-0.0228 points per year (c) The correlation coefficient for the age and safety score of the bridges is R=-0.681. Calculate R2 and interpret it in the above context. Salety score L Most states conduct regular safety checks of bridges, giving a structural deficiency score on various scales. The New York State Department of Transportation uses a scale that runs from 1 to 7, with a score of 5 or less indicating "deficient. Many factors contribute to the deterioration of a bridge, including amount of traffic, material used in the bridge, weather, and bridge design. New York has more than 17,000 bridges. The scatterplot above shows the relationship between the age and safety score of the 194 bridges of Tompkins County. (a) Describe the general relationship/trend between the age and safety score of the bridges of Tompkins County. Intuitively why does the this trend make sense? (b) Given the above data points from the 194 bridge observations, we form the linear least squares model estimate for predicting the safety score of a bridge from its age. Doing so we obtain the following equation of the regression line: safety score=bo + bage where bo = 6.30 Sketch this "best fit" line through the data above and use this model to predict the safety score of a bridge which is 100 years old. and by=-0.0228 points per year (c) The correlation coefficient for the age and safety score of the bridges is R=-0.681. Calculate R2 and interpret it in the above context. Salety score L