The estimated correlation coefficient for the given data pairs is around -0.9, reflecting a strong negative correlation.
The given data pairs suggest a negative correlation, as one variable tends to decrease when the other increases. Visually, it appears to have a moderately strong negative correlation. To estimate the correlation coefficient, one could use a linear regression model or calculate it directly. However, based on the data pattern, a reasonable estimate would be around -0.7 to -0.9.
Among the given options:
a. -0.9
b. 0.4
c. 0.9
d. -0.4
Option (a) -0.9 is the most reasonable estimate given the apparent strong negative correlation in the data.