I have a coordinates that I would like to plot on Google Earth. The coordinates I have appear to be in SAD69, a Brazilian projection. I need to convert them to latitude and longitude.

I tried importing into QGIS as a CSV file in SAD69 and then exporting as a CSV in WGS84. However, the coordinates I have do appear to be in the correct place. My point should be in central Brazil, however when open a SHP file of Brazil and add the point does not appear anywhere near Brazil at all.

The coordinates I have say:

SAD 69, MC 45° W coordenadas Plano Retangulares Relativas, Sistema UTM: E=721320.945 e N =82009367.716 

As I understand it, when importing the coordinates into QGIS, E=721320.945 is my X coordinate and N =82009367.716 would be my Y coordinate. Do I need any other data? I don't understand what MC 45° W means in this context.

Based on the coordinates I have, using the SAD69 projection, the points don't seem to be in Brazil at all.

See screenshot:

I have a coordinates that I would like to plot on Google Earth. The coordinates I have appear to be in SAD69, a Brazilian projection. I need to convert them to latitude and longitude.

I tried importing into QGIS as a CSV file in SAD69 and then exporting as a CSV in WGS84. However, the coordinates I have do appear to be in the correct place. My point should be in central Brazil, however when open a SHP file of Brazil and add the point does not appear anywhere near Brazil at all.

The coordinates I have say:

SAD 69, MC 45° W coordenadas Plano Retangulares Relativas, Sistema UTM: E=721320.945 e N =82009367.716 

As I understand it, when importing the coordinates into QGIS, E=721320.945 is my X coordinate and N =82009367.716 would be my Y coordinate.

Do I need any other data? 

I don't understand what MC 45° W means in this context.

Based on the coordinates I have, using the SAD69 projection, the points don't seem to be in Brazil at all.

See screenshot: