Latitude and Longitude:

Latitude is N/S.  In most computer software, we say that N latitude is positive and S latitude is negative.

Longitude is E/W.  In most computer software, we say that E longitude is positive and W longitude is negative.

Marquette, Michigan is 46 deg 33 min N longitude.
So this 46.55  (since 33 min = 33/60 = 0.55).

And 87 deg 24 min W longitude
So this -87.4 (since w is negative and 24/60 = 0.4)

We can locate this on Google maps:

https://google.com/maps/@46.55,-87.4

The @ tells maps we're talking latitude and longitude.  Notice that latitude is listed first.