The weights of 31 Jersey cows were recorded to the nearest kilogram. The weights are shown in the table. Weight of cattle (kg) Frequency Cumulative frequency 300-349 3 350-399 6. 400-449 10 450-499 7 500-549 5 a Complete the cumulative frequency column in the table. b Find the lower quartile, Q c Find the upper quartile, Q. d Find the interquartile range.