Part 1: The correct regression line is $y = 0.750x + 48.28$, which corresponds to option A.

Part 2: The coefficient of correlation $r$ is $0.985$, indicating a very strong positive linear relationship.

Additionally, using the regression line to predict the life expectancy in the year 2010 (11 decades after 1900), we estimate it to be approximately 56.53 years.

Do you want more details or have any questions?

Here are 5 related questions:

1. How is the coefficient of correlation interpreted in this context?
2. What does the slope of the regression line represent in terms of life expectancy?
3. How could you calculate the life expectancy for other years using the regression equation?
4. What does a strong correlation coefficient suggest about the reliability of the prediction for 2010?
5. Can we use this regression model for predicting life expectancy far beyond 2010?

Tip: Always verify if a linear relationship holds true by checking the correlation coefficient; values near 1 or -1 indicate strong linearity.