Final answer:
The sum of material price variance and material quantity variance is known as the total cost variance, which provides an overall picture of the variance in material costs within cost accounting.
Step-by-step explanation:
The student has asked about the relationship between different types of variances in cost accounting. Specifically, the sum of the material price variance (calculated at the point of purchase) and material quantity variance is known as the total cost variance.
The material price variance reflects the difference between the actual price paid for the materials and the standard cost, while the material quantity variance reflects the difference between the standard quantity expected to use and the actual quantity used. When added together, they provide an overall picture of the variance in material costs.