The richter scale measures the intensity of earthquakes on a logarithmic scale. the magnitude of an earthquake on the richter scale can be defined by m=2/3log(e)-3.2, where e is the energy of the quake in joules. the 2011 tohoku earthquake in japan measured 9.1 on the richter scale. the 1999 hector mine earthquake in eastern california had a magnitude of 7.1. calculate the energy released by each earthquake.

An annual marathon covers a route that has a distance of approximately 26 miles. winning times for this marathon are all over 2 hours. the following data are the minutes over 2 hours for the winning male runners over two periods of 20 years each. earlier period 14 12 15 22 13 10 19 13 9 14 20 18 16 20 23 12 18 17 6 13 recent period 7 11 7 14 8 9 11 14 8 7 9 8 7 9 9 9 9 8 10 8 (a) make a stem-and-leaf display for the minutes over 2 hours of the winning times for the earlier period. use two lines per stem. (use the tens digit as the stem and the ones digit as the leaf. enter none in any unused answer blanks. for more details, view how to split a stem.) minutes beyond 2 hours earlier period 0 1 2 (b) make a stem-and-leaf display for the minutes over 2 hours of the winning times for the recent period. use two lines per stem. (use the tens digit as the stem and the ones digit as the leaf. enter none in any unused answer blanks.) minutes beyond 2 hours recent period (c) compare the two distributions. how many times under 15 minutes are in each distribution

Erik buys 2.5 pounds of cashews. if each pound of cashews costs $7.70, how much will he pay for the cashews?

4. bob solved the inequality problem below incorrectly. explain his error and redo the problem showing the correct answer. ? 2x + 5 < 17 ? 2x + 5-5 < 17-5 -2x/-2 < 12/-2 x < -6