An investigation of the relationship between traffic flow (measured in cars per day) and lead content (measured in micrograms per gram of dry weight) in the bark of trees near the highway yielded the following summary statistics: Sample Mean Sample Standard Deviation Lead Content (micrograms per gram dry weight) y¯=y¯= 680 sysy = 240 Traffic Flow (cars / day) x¯=x¯= 1750 sxsx = 800 The correlation between lead content and traffic flow was found to be r = 0.6 and a scatterplot showed the form to be linear. The least squares regression line for using X to predict Y was found to be y^=365+0.18xy^=365+0.18x. For trees in a given area, if the traffic flow is 14,000 cars per week, predict the lead content in their bark. Note: the traffic flow given in this question is NOT in the same units as the values used to calculate the line. Given value of x = 14,000 cars per week equals how many cars per day Predicted Value of y is how many micrograms per gram of dry weight
Inverse Normal Distribution
The method used for finding the corresponding z-critical value in a normal distribution using the known probability is said to be an inverse normal distribution. The inverse normal distribution is a continuous probability distribution with a family of two parameters.
Mean, Median, Mode
It is a descriptive summary of a data set. It can be defined by using some of the measures. The central tendencies do not provide information regarding individual data from the dataset. However, they give a summary of the data set. The central tendency or measure of central tendency is a central or typical value for a probability distribution.
Z-Scores
A z-score is a unit of measurement used in statistics to describe the position of a raw score in terms of its distance from the mean, measured with reference to standard deviation from the mean. Z-scores are useful in statistics because they allow comparison between two scores that belong to different normal distributions.
An investigation of the relationship between traffic flow (measured in cars per day) and lead content (measured in micrograms per gram of dry weight) in the bark of trees near the highway yielded the following summary statistics:
| Sample Mean | Sample Standard Deviation | |
| Lead Content (micrograms per gram dry weight) | y¯=y¯= 680 | sysy = 240 |
| Traffic Flow (cars / day) | x¯=x¯= 1750 | sxsx = 800 |
The
The least squares regression line for using X to predict Y was found to be y^=365+0.18xy^=365+0.18x.
For trees in a given area, if the traffic flow is 14,000 cars per week, predict the lead content in their bark.
Note: the traffic flow given in this question is NOT in the same units as the values used to calculate the line.
Given value of x = 14,000 cars per week equals how many cars per day
Predicted Value of y is how many micrograms per gram of dry weight
Trending now
This is a popular solution!
Step by step
Solved in 2 steps
