# Looking to calculate how many perfect surveys to hit the goal

1. ## Looking to calculate how many perfect surveys to hit the goal

Need to calculate how many Customer Satisfaction Surveys with a score of 10 are needed to return to a goal of 9.75

If a survey is received with a score of zero, thirty nine surveys at 10 are needed to reach a goal of 9.75

The link below seems to have had this same question and/or answer, however it has been removed.
http://www.excelforum.com/excel-form...-the-goal.html  Register To Reply

2. ## Re: Looking to calculate how many perfect surveys to hit the goal

This isn't really an excel question, but instead, middle-school algebra.

Variables:
Known:
Nx = number of existing surveys
Sx = sum of values of existing surveys
G = goal for the average
Unknown:
N10 = number of perfect surveys (eg, result of 10)

Expression:
(Sx + 10 * N10) / (Nx + N10) = G
;; sum / count = average

Rearranging:

N10 = (G * Nx - Sx) / (10 - G)

Replace the variables with cell references, and that's good-to-go for excel.  Register To Reply

3. ## Re: Looking to calculate how many perfect surveys to hit the goal

Basically as stated above it's pretty basic math (for some) to get target #.

1. In column A place each survey score.
2. In B1 place your goal (9.75)
3. In C1 paste the Formula below.

Each time you add a score to coulmn A the number of 10's needed will update in C1. ``Please Login or Register  to view this content.``  Register To Reply

4. ## Re: Looking to calculate how many perfect surveys to hit the goal

Thank you

PHP Code:
```     A            B1    9.702380952   Current CSat average2    12            Number of surveys received3    9.75          Target Goal4    10            Max Score5    3             Max scores required to meet goalEntered into B5 =CEILING(B2*(B1-B3)/(B3-B4),1)  ```  Register To Reply