ADJ. high, low | male/female, pupil/teacher, etc. | benefit-to-risk, power-to-weight, etc.
VERB + RATIO achieve, have They have a high ratio of imports to exports. | improve, increase The hospital is trying to improve its staff/patient ratio. | reduce | calculate, find, work out
RATIO + VERB improve | worsen the worsening pupil/teacher ratio in our schools
PREP. in a/the ~ We mixed the oil and water in a ratio of one to five. | ~ between the ratio between the amount of time spent on the work and the profit produced | ~ of sth to sth the ratio of house prices to incomes
PHRASES in direct ratio to sth Their sales rose in direct ration to the amount they spent on advertising.