Please choose the correct ending to complete the given sentence: Computers and Electronics: [header] How to read an ekg [title] Understand the grids of an ekg paper printout. [step] Voltage-the electrical signals of the heart-is measured along the vertical axis; time is measured along the horizontal axis in squares. There are large squares that are divided into smaller squares.

Ending1: Simply multiply the number (letters together) under each square-this means that there are at least 12 squares of the printout. [substeps] Measurement of time is dependent on the number of squares of the printout. Ending2: Common table sizes of graph paper are ods scale taken at work, lolus scale taken at home, etc. [substeps] The grids let you view peaks and valleys, as shown in the image. Ending3: [substeps] Small squares are 1 mm across and represent 0.04 seconds. The large squares measure 5 mm across and represent 0.2 seconds. Ending4: [substeps] Double check each set of squares to make sure that the comparison is accurate. Check the denominator within each square for accuracy.

Answer format: ending1/ending2/ending3/ending4