The ages of rocks can be determined using the isotope 135cs, which undergoes beta decay with a half-life of 2. 3×106 y. A rock sample contains a ratio of 135ba to 135cs of 0. 15. Given that 135ba is a stable product of the beta decay of 135cs, and assuming there was originally no 135ba present in the rocks, calculate the age of the rock sample.

olivia is the best example for presentating so it would be d.

the histogram that represents the data with the largest spread is data set b

answer:

i havent taken the psat, but i have the sat, make sure to bring some snacks, because youre in there forever, 2 sharp number two pencils, an sat approved calculator, and maybe a jacket.   your phone and any books will be taken up, so don't try to bring them(but they will be given back at the end of the testing).   good luck!   i hope you do well!