Question

You use a line best fit for a set of data to make a prediction about an unknown value. The correlation coefficient for your data set is -0.993. How confident can you be that your predicted value will be reasonably close to the actual value?
a. I can't be confident at all; this is about as close to a random guess you could get
b. I can be a little confident; it might be close, or it might by way off
c. I can be very confident; it will be close, but it probably won't be exact
d. I can be certain that my predicted value will match the actual value exactly
I think it's c, but I'm not so sure. Please help :)

Answer 1

The value will never be exactly the same as the line, especially in statistics because the world isn’t perfect, so the answer would be C. Plus, mathematically, it still is off by about -.07 to be a “perfect” match.

Answer 2

Solution:

Correlation Coefficient (r) tells the relationship between two variables, as well as line of best fit also determines the correlation between two variables. if the points are close to line of best fit it means variables are closely related with each other.

Correlation coefficient = - 0.993 , shows strong disagreement between two variables.

As line of best fit and Correlation coefficient , both of them approximately gives the same value of correlation.

Option (C) :  I can be very confident; it will be close, but it probably won't be exact is true statement.