In a hearing on a petition to revoke probation, the burden is upon the State to prove a violation of a condition of a probationary sentence by a preponderance of the evidence. On appellate review, the trial court's findings are upheld unless they are clearly against a preponderance of the evidence. Hyde v. State, 59 Ark. App. 131, 953 S.W.2d 911 (1997). Since the determination of the preponderance of the evidence turns upon questions of credibility and weight to be given testimony, this court defers to the trial court's superior position. Id. In Baldridge v. State, 31 Ark. App. 114, 789 S.W.2d 735 (1990) a failure to complete a condition is not grounds for revocation where there has been an excusable failure.