What is the test for setting aside a sentence when there is evidence that the sentence was improper?

fatal to a sentence. (People v. Price (1991) 1 Cal.4th 324, 492, called into doubt on other grounds by People v. Hinks (1997) 58 Cal.App.4th 1157, 1161-1165.) "When a trial court has given both proper and improper reasons for a sentence choice, a reviewing court will set aside the sentence only if it is reasonably probable that the trial court would have chosen a lesser sentence had it known that some of its reasons were improper. [Citation.]" (People v. Price, supra, 1 Cal.4th at p. 492.)