How to Calculate the average flux of sunlight at the equator?

Calculate the average flux of sunlight at the equator. Assume that the sun supplies 1368 joule/(meter2 second) and that 30 percent of the sunlight is reflected away. Assume it is night half the time, and the sun shines directly overhead at noon. The average value of the sine function over half a cycle is 2/蟺.|||The haze and dust at near-twilight reduces incident from pure function expectations, but let's assume it doesn't, and a solar collector is flat on the ground. Obviously it's the vernal equinox. Flux density is measured in joule/meter^2, a rate, not a quantity. The average value of SIN over a half cycle is not 2/pi. The integral of SIN zero to either pi/2 or pi because symmetry is involved, in this case where K=0 and peak value is unity, is 2^-2/2. So 1368 times 70% times 2^-2/2 = 677 joule/meter^2. Isn't Calculus fun? Regards, Larry.