how do i do this with a calculator

1. The graph alongside shows the world record times for the Ay (S) women's 400 m. between Marlene Mathews' record of 56 10 57.0 s on January 6. 1957 and Marita Koch's record of 54 47.60 s on October 6, 1985. The data is modelled with the straight line y = 54.85-0.2660.r where y is the time 52 in seconds and a is the number of years since 1957. 50 a What does the model predict the time will be in 18 1957? What was the time, and why are these values different? 46 b Could the model be used to estimate world record (years) times prior to 1957? Explain your answer. 10 20 30 Florence Griffith-Joyner holds the women's 100 m record of 10.49 s. In what year does this model predict the women's 400 m will be completed in 10.49 x 4 = 41.96 s? d Marita Koch's time of 47.60 s is still the world record in 2018. Discuss the reliability of this model for predicting future world record times. (Update: As of August 2024, this is still the world record for the women's 400 m.)