What's the correct code look like? I have less than 24hours to figure this out and pass, new so please give solution

var myBirds = new List<Bird> 
{ 
    new Bird { Name = "Cardinal", Color = "Red", Sightings = 3 },
    new Bird { Name =  "Dove", Color = "White", Sightings = 2 },
    new Bird { Name =  "Robin", Color = "Red", Sightings = 5 }
};

var yourBirds = new List<Bird> 
{ 
    new Bird { Name =  "Dove", Color = "White", Sightings = 2 },
    new Bird { Name =  "Robin", Color = "Red", Sightings = 5 },
    new Bird { Name =  "Canary", Color = "Yellow", Sightings = 0 }
};

var ourBirds = myBirds.Join(yourBirds,
                            mb => mb.Name,
                            yb => yb.Name,
                            (mb, yb) => (mb));

var sumOfSightings = ourBirds.Sum(ob => ob.Sightings);
var averageSightings = ourBirds.Sum(ob => ob.Sightings);