Express 10 1/4 - 4 1/2 as a decimal

Hi, can anyone show me how to do this problem? 100 points for this. in advance

Data for the height of a model rocket launch in the air over time are shown in the table. darryl predicted that the height of the rocket at 8 seconds would be about 93 meters. did darryl make a good prediction? yes, the data are best modeled by a quadratic function. the value of the function at 8 seconds is about 93 meters. yes, the data are best modeled by a linear function. the first differences are constant, so about 93 meters at 8 seconds is reasonable. no, the data are exponential. a better prediction is 150 meters. no, the data are best modeled by a cubic function. a better prediction is 100 meters.

Mallory has been offers two different jobs. she can baby sit for 6 hours a week and get $8.50 an hour. or she can work at the library for 14 hours a week and make $5.50 an hour. which job will allow her to save the most money after 6weeks?