In recent years, a number of companies have been formed that offer competition to at& t in long-distance calls. all advertise that their rates are lower than at& t’s, and as a result their bills will be lower. at& t has responded by arguing that for the average consumer there will be no difference in billing. suppose that a statistics practitioner working for at& t determines that the mean and standard deviation of monthly long-distance bills for all its residential customers are $17.09 and $3.87, respectively

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.