Under the Brendan Dennehy Case Scenario practice q I see in the regression table that significance of F is 0 and the f statistic is 157. What does significance of 0 mean exactly? Is this a 0% confidence interval if so does it make that f stat insignificant. Bit confused about how to interpret this significance as 0 exactly.

Maybe you mean p-value is ~0…

Significance level when listed in regression results is referring to the p-value (i.e. the lowest level of significance that the null hypothesis can be rejected). In other words, a significance of 0 means there is no level of confidence too high (95%, 99%, etc.) wherein the null hypothesis would not be able to be rejected. Also, confidence = 1 - significance level, so 1 - 0% significance level = 100% confidence.

This conclusion is supported by the extremely high f score.

“is there is no level of confidence too high (95%, 99%, etc.) wherein the null hypothesis would not be able to be rejected” - sorry double negatives always trip me up. so basically you are saying that null hypothesis will be rejected at any level. right?

Yes that’s right.

I would be careful in the real world with this kind of thinking. The p-value is practically never zero, even in this example, it is just rounded from the computer. A 100% CI would be consistent with an interval that encompasses all possible values, making the interval useless.

Not that this is likely for the exam, but remember that a real world exists, and you may find yourself using this stuff one day.