DEFINE

MEASURE 'Internet Sales'[Sum_X] = SUM('Internet Sales'[Order Quantity]) -- replace with any measure/calculate

MEASURE 'Internet Sales'[Sum_Y] = SUM('Internet Sales'[Sales Amount]) -- replace with any measure/calculate

MEASURE 'Internet Sales'[Sum_XY] = SUMX(VALUES(Customer[Customer Id]), [Sum_X] * [Sum_Y]) -- replace Customer[Customer Id] with any column u want

MEASURE 'Internet Sales'[Sum_X2] = SUMX(VALUES(Customer[Customer Id]), [Sum_X] * [Sum_X]) -- replace Customer[Customer Id] with any column u want

MEASURE 'Internet Sales'[Sum_Y2] = SUMX(VALUES(Customer[Customer Id]), [Sum_Y] * [Sum_Y]) -- replace Customer[Customer Id] with any column u want

MEASURE 'Internet Sales'[Count_Items] = DISTINCTCOUNT(Customer[Customer Id]) -- replace Customer[Customer Id] with any column u want

MEASURE 'Internet Sales'[Pearson_Dividend] = ([Count_Items] * [Sum_XY]) - ([Sum_X] * [Sum_Y])

MEASURE 'Internet Sales'[Pearson_Divisor_X] = ([Count_Items] * [Sum_X2]) - ([Sum_X] * [Sum_X])

MEASURE 'Internet Sales'[Pearson_Divisor_Y] = ([Count_Items] * [Sum_Y2]) - ([Sum_Y] * [Sum_Y])

MEASURE 'Internet Sales'[Pearson_Divisor] = SQRT([Pearson_Divisor_X] * [Pearson_Divisor_Y])

MEASURE 'Internet Sales'[Pearson] = DIVIDE([Pearson_Dividend], [Pearson_Divisor])

EVALUATE
ADDCOLUMNS(
	ALL('Date'[Calendar Year]),
	"X-Value", [Sum_X],
	"Y-Value", [Sum_Y],
	"Pearson", [Pearson]
)