The chart below shows the world records for the women’s 10,000 meter run in the years 19...

The chart below shows the world records for the women’s 10,000 meter run in the years 1970 and 1993.

For the years between 1970 and 1993, the world record can be approximated by the equation

where y is the world-record time (in seconds) in the year t. Use the given equation, the quadratic formula, and your calculator to estimate the year in which the record might have been 32 minutes (=1920 seconds). (As in Exercise 21, you’ll get two solutions for the quadratic; pick the appropriate one.) Then say by how many years your prediction is off, given the following information:

On September 19, 1981, Yekena Sipatova of the former Soviet Union ran a record time of 32:17.2; in the following year on July 16, Mary Decker of the United States ran 31:35.3. (Note:Wang Jinxia’s 29:31.78 was still the world record in 2008.)