The following bar graph gives figures for the production of fans and of coolers by a large company in four consecutive years. Calculate the ratio of the number of fans produced in 1998 to the number of coolers produced in 2001.

23 : 18 32 : 18 23 : 21 18 : 23

23 : 18

Number of fans produced in 1998  :  Number of coolers produced in 2001   23  :  18