Hey there!
El Nino typically involves waters with a warmer than usual surface temperature, a flatter thermocline (cooler water moves to the surface), and weaker trade winds. As for La Nina, think of it as the opposite of El Nino. There will be stronger trade winds, and cooler surface water temperatures.
Hope this helps!
The correct answer is: The correlation coefficient = -0.62.
This is shown in the experimental studies. It is shown that prevalence of caries is 62% lower in children who brush their teeth few times a day when compared to those who never brush their teeth.