$4.$ Suppose that, at the beginning of the semester $$1\mathrm{.}08$ would purchase $1\mathrm{.}00$ Euro. Suppose, also, that it now takes $$1\mathrm{.}17$ to purchase $1\mathrm{.}00$ Euro. Also, suppose that at the beginning of the semester, $$1\mathrm{.}2739$ purchased $1\mathrm{.}00$ while it now takes $$1\mathrm{.}2564$ to purchase $1\mathrm{.}00.$ At the same time, at the start of the semester, the $$1$ would purchase $146\mathrm{.}39$ Japanese Yen while $$1$ will now purchase $150\mathrm{.}81$ Japanese Yen. Has the U$.$S$.$ $ gotten stronger or weaker versus each these currencies over the past month? Identify and explain events in the U$.$ S$.$ economy that might cause these exchange rates to change as they have.