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.
Answer:
100⁰
because this is a quadrilateral inscribed in the circle
=> x + 80 = 180
<=> x = 180 - 80 = 100⁰
Answer:
Each batch of scones needed 0.67 kg of flour
Step-by-step explanation:
16.45 - 6.4 = 10.05kg (remaining)
15 batches = 10.05kg
1 batch = 0.67kg
Answer:
about 70 years
Step-by-step explanation:
Life expectancy (e) improves by 5.7 years every 10 years, so 5.7/10 = 0.57 years per year. For t years after 2009, it can be modeled by ...
e = 0.57t +80
We want to find when that is 120:
120 = 0.57t +80
40 = 0.57t
40/0.57 = t ≈ 70.2
About 70 years from 2009, humanity may achieve a life expectancy of 120 years.