How to do calculated values in Excel Pivot Table - excel

Question

I have a table like this:
Year Num Freq. Exam Grade Course
2014 102846 SM SM Astronomy 3
2015 102846 12,6 1,7 NC Astronomy 2
2017 102846 20 11,8 17 Astronomy 2
2015 102846 SM NC Defence Against the Dark Arts 4
2015 102846 11 4,5 NC Herbology 2
2015 102846 15 13,99 14 Herbology 2
I am trying to get the percentage of approved students (Grade >= 10) for each course by year and global average.
I've been trying for nearly 3 hours to do a calculated field but so far the only thing I could get was the sum of each student per year:
I have tried to do a calculated field with = Grade >= 10 hoping that it would give me a list of approved students but it gives me 1.
What am I doing wrong in here? It's my first time working with pivot tables.

Answer 1

I would really recommend to not mix string type (text) together with numbers. It's a horrifying idea and will cause a lot of headache when data will be used for calculations (both Freq. and Grade). Rather I would use 0 or some numeric value to represent the text.
Not recommended, but yes it's doable =)
You need some dummy variable to point out which row is number and which is text. So I created Grade Type. We can now count only the rows that have a number in the Grade column by using Grade Type = Number.
I create a table of the data and add the column Grade Type. I use this formula to get Grade Type:
=IF(ISNUMBER([#Grade]),"Number","Text")
I then create the following measures:
Nr of Approved Students
=COUNTX(FILTER(Table1, Table1[Grade Type]="Number"),
IF((VALUE(Table1[Grade])>=10),VALUE(Table1[Grade]),BLANK()))
First we filter which rows that should be evaluated (COUNTX(<table>,...)). If yes, then only count for rows that fulfill >=10, where VALUE() converts string number to numeric (COUNTX(...,<expression>)).
Nr of Student (w/ Grade Number)
=COUNTX(FILTER(Table1, Table1[Grade Type]="Number"), VALUE(Table1[Grade]))
Count all rows that have a number
Approved (% of Total)
=[Nr of Approved Students]/[Count of Grade]
Setup the PowerPivot Table
Create the PowerPivot and add the data to the data Model
Then create a new measure by clicking your pivot table and then "Measures" -> "New Measure..."
Fill in all the relevant data.
Result should be something like: