Most Analysts Focus on the Cost of Tuition as the Way

Most analysts focus on the cost of tuition as the way to measure the cost of a college education. But incidentals, such as textbook costs, are rarely considered. A researcher at Drummand University wishes to estimate the textbook costs of first-year students at Drummand. To do so, she monitored the textbook cost of 250 first-year students and found that their average textbook cost was $300 per semester. Identify the variable of interest to the researcher.

A) the age of Drummand University students
B) the cost of incidental expenses of Drummand University students
C) the year in school of Drummand University students
D) the textbook cost of first-year Drummand University students