that would appear to be your read-only (ro) cause. a couple thoughts on how to get it to be rw. this command that i learned from @Akito:
replacing /dev/sda1 with your drive /dev/sdb1 and then keeping in mind that you need to create the mount point for it to appear in. something like /home/easyt50/mnt/Data (or wherever you choose) seems like it should work.
the other option is that the disks utility allows you to edit the mount options. when i select my external from the list of drives in the left pane, its description appears in the right pane. underneath a rectangular representation of the disk partition there is a small (farthest right) button that looks like gears. the fifth choice down is edit mount options and i am wondering if you could signify rw there.