Assume that you have paired values consisting of heights (in inches) and weights (in lb) from 40 randomly selected men. The li
1 answer:
Answer:
B. The coefficient of determination is 0.1980, 19.8% of the variation is explained by the linear correlation, and 80.2% is explained by other factors.
Step-by-step explanation:
Previous concepts
The correlation coefficient is a "statistical measure that calculates the strength of the relationship between the relative movements of two variables". It's denoted by r and its always between -1 and 1.
Solution to the problem
In order to calculate the correlation coefficient we can use this formula:
On this case we got that r =0.445
The determinaton coefficient is just:
And we can put it on % and we got 19.8%. And represent the variation explained by a linear model. The best option on this case would be:
B. The coefficient of determination is 0.1980, 19.8% of the variation is explained by the linear correlation, and 80.2% is explained by other factors.
Since the explained variation is 19.8% and the remain 100-19.8= 80.2% is explained by other factors.
You might be interested in
Answer:
The top 20% of the students will score at least 2.1 points above the mean.
Step-by-step explanation:
When the distribution is normal, we use the z-score formula.
In a set with mean and standard deviation
, the zscore of a measure X is given by:
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.
The mean of a certain test is 14 and the standard deviation is 2.5.
This means that
The top 20% of the students will score how many points above the mean
Their score is the 100 - 20 = 80th percentile, which is X when Z has a pvalue of 0.8. So X when Z = 0.84.
Their score is:
16.1 - 14 = 2.1
The top 20% of the students will score at least 2.1 points above the mean.