Using UN data from 1975 and projections to 2050, the number of millions of people age 15 to 59 in a country can be modeled by y=-0.22x squared +23x+372.7, with x equal to the number of years after 1970 and y equal to the number of millions of people in this labor pool. Use technology with the model to fine when this population is expected to be equal to 921.3 million. the model indicated that the countrys population is expected to be equal to 921.3 million in the years