1. M. Munda Company produces and sells rattan baskets. The number of units produced and the corresponding total production costs for six month, w hich are representatives for the year, are as follows:

Month Units produced Production costs

April 500 P4, 000

May 700 P8, 000

June 900 P6, 000

July 600 P7, 500

August 800 P8, 500

September 550 P7, 250

The monthly production cost can be expressed as

1. Y = a + bx
2. Y = b +ax
3. Y = ax + b
4. X = a +by