Refer to figure.
Step 1: Calculate pressure altitude

The pressure difference between actual QNH and standard is 1023 - 1013 = +10 hPa. 

Each 1 hPa above standard lowers the pressure altitude by approximately 30 ft, so the correction is +10 × 30 = 300 ft to subtract from the elevation.

Pressure altitude = 2800 - 300 = approximately 2500 ft.

Step 2: Draw on chart

With a pressure altitude of roughly 2500 ft, OAT of +10°C, and weight of 2250 lbs, the chart is entered at the temperature axis at +10°C, a line is drawn up to intersect the pressure altitude curve interpolated between 2000 ft and 4000 ft (closer to 2000 ft), then horizontally to the weight reference line, adjusted for 2250 lbs (between 2100 and 2500 lbs), and finally projected horizontally into the wind section at zero wind, reading the ground roll. 

The result obtained from this process is approximately 675 ft.