Figuring out slope without Slope function

[DNow5577]

I am having to use a program for work that cannot use the slope function like in excel. I am trying to figure out the slope by calculating it out. Below is the x,y values to calculate slope. 

X	Y
14	15.34
16.7	17.07
17.5	18.92
Sum 48.2	Sum 51.33
AVG 16.07	AVG 17.11

I read online that the below formula is to calculate slope. I enter this formula in excel and it works. I get the same answer using this formula as SLOPE function, which is .9257 or .93

=SUM((A75:A77-AVERAGE(A75:A77))*(B75:B77-AVERAGE(B75:B77)))/SUM((A75:A77-AVERAGE(A75:A77))^2)

BUT, the problem is I am not able to use this formula in the program for work either. I need to calculate this out and this is what I do with the formula below. The thing is, when I use the below formula I get 1.06 and it should be .93

=((48.2-(16.07))*(51.33-(17.11)))/((48.2-(16.07))^2)

Does anyone know how to write this above formula to get the correct answer of .93?

I feel like I am missing a parentheses somewhere or reading the SUM/AVERAGE formula wrong. 

[#2 · Accepted solution]

@DNow5577  

Hi Daniel, Sum und AVERAGE Spills, so you have 3 calculations.

This formula results in0.925:

=(((14-16.0667)*(15.34-17.11))+((16.7-16.0667)*(17.07-17.11))+((17.5-16.0667)*(18.92-17.11)))/(((14-16.0667)^2)+((16.7-16.0667)^2)+((17.5-16.0667)^2))