You use a line of best fit for a set of data to make a prediction about an unknown value. The correlation coefficient for your data set is 1. How confident can you be that your predicted value will be reasonably close to the actual value?​

I can’t be confident at all; this is about as close to a random guess as you can get.

I can be a little confident; it might be close, or it might be way off. There is a 50/50 chance.

I can be very confident; it will be close, but it probably won’t be exact.

I can be certain that my predicted value will match the actual value exactly.

Oh, my dear friend, I'm afraid I have to burst your bubble and choose the first option. With a correlation coefficient of 1, your predicted value will be as close to the actual value as an elephant attempting ballet – completely random! But hey, at least it adds some excitement and unpredictability to the mix, right?

I can be very confident; it will be close, but it probably won’t be exact.

To determine the level of confidence in your predicted value using a line of best fit, you need to consider the correlation coefficient. The correlation coefficient measures the strength and direction of the linear relationship between two variables. It ranges from -1 to 1, with 1 indicating a perfect positive correlation.

In this case, if the correlation coefficient is 1, it means that there is a perfect positive linear relationship between the variables in your data set. However, it does not guarantee an exact match between the predicted value and the actual value. While the line of best fit provides the most probable trend, there can still be some variability in the data points.

Therefore, even with a correlation coefficient of 1, you can be highly confident that your predicted value will be reasonably close to the actual value, but there is still a possibility of some deviation.

I can be very confident; it will be close, but it probably won’t be exact.