I am new to ArcGIS and have been to the basic courses but I'm not understanding how to get my Excel spreadsheet into my Arcmap. I have created a spreadsheet that has longitude and latitude decimal format that I am wanting to be able to plot on my map. I can get the data into the map but it does not appear to be plotting correctly. My X axis is my long and my Y axis is my lat, I have the coordinate system set. Please help.
Are the points plotting at all? If they are not it may be a conflict issue with the projection and the data frame. Is there existing data in the map or just the excel file?
If the points are not plotting at all, the field which the xy data is in may be of text format or general format which will not convert on the fly when bringing into ArcGIS.
I think it is very important to understand what projection your data is in.It really depends on what extent you work over but you should be aware of most datums and projections in your local area and be able to identify them by numbers. For example there are four main projections I deal with at work. From simply looking at the coordinates numbers I can identify which datum and projection they are in. It can make your life a lot easier if you know at least the main ones used in most of your jobs.
Ok...I see your problem here. Your coordinates are in decimal degrees and the linear units for the state plane are US Survey Feet. What you will need to do is open up a blank MXD and set the data frame projection to something like the NAD 83 Geographic Coordinate System or WGS 84. Then display your xy data here and export the XY event layer to a shapefile. Once you have done this you can then use the Project tool to project the shapefile you just made to the the NAD_1983_StatePlane_Oklahoman_North_FIPS_3501_Feet. This should properly project your coordinates in the state plane projection.