Asample of a radioactive isotope had an initial mass of 690 mg in the year 1997 and decays exponentially over time. a measurement in the year 2001 found that the sample's mass had decayed to 390 mg. what would be the expected mass of the sample in the year 2011, to the nearest whole number?

Harry’s soccer team plays 2 nonconference games for every 3 games that they play against conference opponents. if y represents the number of nonconference games and x represents the number of conference games, which equation best models this proportional relationship? a)y=2/3 x b)y=3/2 x c)y = 2x d)y = 6x

The estimated number of people to attend the last bengals game of the season was 2000. the actual number of fans attending was 1200. by what percent did the estimate differ from the actual?

Kai walked one and two-thirds of a mile on saturday and four and one-sixth of a mile on sunday. how many miles did kai walk?