The table shows a company's income and expenses over the last 7 days.

Day

of Income Expenses

Week

Sun. $169. 56 $ 256. 25

Mon. $217. 61 $ 195. 79

Tues. $150. 89 $1208. 55

Wed. $409. 73 $ 709. 11

Thurs. $687. 45 $ 190. 98

Fri. $1,563. 09 $ 325. 78

Sat. $1,267. 92 $ 315. 64

The company found that its weekly income and expenses were approximately the same from week to week.

Select the correct definition of the variable X

O X = number of weeks

O X = weekly expenses

O X = day of the week

O X = weekly income