I need answer and explanation

Q). Dunklin Medical Clinic measures its activity in terms of patient-visits. Last month, the budgeted level of activity was 1,620 patient-visits and the actual level of activity was 1,540 patient-visits. The cost formula for administrative expenses is $3.20 per patient-visit plus $14,300 per month. The actual administrative expense was $21,050. In the clinic's flexible budget performance report for last month, the spending variance for administrative expenses was: (REQURIED)