Hi. Thank you for these videos. I just have a question. When I solved this via the Ti-84, the equation of the linear regression I got was y= 1320.53X - 6627.65. Is there a reason for the discrepancy? Thanks again. I really appreciate all your videos.
Any discrepancy is likely due to how I performed the rounding. Calculators can hold almost every digit required for the calculation in memory, while as a human I usually round to 2-4 decimal places (although, the difference between "6627.65" and "6499.51" is kind of big, so I'll double-check my calculations when I get the chance).
When your finding B1. Why when solving for Sx and Sy do you put the equation above N-1. What is the N-1 there for? It wasn't in the problem when you did Pearson's correlation.
n - 1 represents the degrees of freedom when calculating standard deviation (Sx and Sy). The bottom parts of the Pearson's r equation are not Sx and Sy, but are actually Sums of Squares (SSx and SSy). Sums of Squares in this equation don't have degrees of freedom.
I watched this because I have a test on this tomorrow. After watching it, I realized just how fucked I am.
Mattthornz 3 weeks ago
@Mattthornz
That's rough. Send me an email if you have any questions and I'll try to answer them.
statslectures 3 weeks ago
Hi. Thank you for these videos. I just have a question. When I solved this via the Ti-84, the equation of the linear regression I got was y= 1320.53X - 6627.65. Is there a reason for the discrepancy? Thanks again. I really appreciate all your videos.
J0se4Jesus 1 year ago
@J0se4Jesus
Any discrepancy is likely due to how I performed the rounding. Calculators can hold almost every digit required for the calculation in memory, while as a human I usually round to 2-4 decimal places (although, the difference between "6627.65" and "6499.51" is kind of big, so I'll double-check my calculations when I get the chance).
statslectures 1 year ago
When your finding B1. Why when solving for Sx and Sy do you put the equation above N-1. What is the N-1 there for? It wasn't in the problem when you did Pearson's correlation.
zhunterzz1 1 year ago
@zhunterzz1
n - 1 represents the degrees of freedom when calculating standard deviation (Sx and Sy). The bottom parts of the Pearson's r equation are not Sx and Sy, but are actually Sums of Squares (SSx and SSy). Sums of Squares in this equation don't have degrees of freedom.
statslectures 1 year ago