A sample of a radioactive isotope had an initial mass of 640 mg in the year 2010 and decays exponentially over time. A measurement in the year 2014 found that the sample's mass had decayed to 440 mg. What would be the expected mass of the sample in the year 2024, to the nearest whole number?

Given: lines a and b are parallel and line c is a transversal. prove: 2 is supplementary to 8 what is the missing reason in the proof? statement reason 1. a || b, is a transv 1. given 2. ∠6 ≅ ∠2 2. ? 3. m∠6 = m∠2 3. def. of congruent 4. ∠6 is supp. to ∠8 4. def. of linear pair 5. ∠2 is supp. to ∠8 5. congruent supplements theorem corresponding angles theorem alternate interior angles theorem vertical angles theorem alternate exterior angles theorem