pca9564 = i2c bus controller

i read that the resistances in sda & scl (I2C) are typically 10Kohm for 100KHz and 2Kohm for 400 KHz, is this true? or how can i calculate them, i read lots of datasheets and all i got were this typically values.
i also found this formula R = tr / CBUS (datasheet pcf8570). how can there can be typical values if the CBUS changes from application to application