Tech Innovations Inc. utilizes standard costing for its production process. The standard direct materials cost per unit is $20, and the standard direct labor cost per unit is $15. During the month, 5,000 units were produced. Actual direct materials costs were $98,000, and actual direct labor costs were $72,000. Calculate the direct materials price variance, direct materials quantity variance, direct labor rate variance, and direct labor efficiency variance. Provide an analysis of each variance and potential causes.