A galaxy cluster has a galaxy behind it whose image we see as being smeared out and curved, with an angular radius of curvature on the sky of E. The background galaxy is at redshift zgal and the cluster is at zclust. What is the mass of the cluster in solar masses? Give your response in scientific notation with one decimal place. (The Hubble constant is of course 70 km/s/Mpc, and you can assume the Hubble law for these low redshifts). Values: zgal = 0.12 zclust = 0.07 E = 145.1 arcseconds