Once you see (in plain text and not on a chart) the output coming from the Micro you will have a better idea about your problem.
void loop()
{
Serial1.print(analogRead(xpin));
Serial1.print(analogRead(ypin));
Serial1.print(analogRead(zpin));
delay(100);
}
The analogRead() function returns an integer between 0 and 1023. The print function formats this integer in ASCII and sends it out the serial port. So assuming that the three analog values are 876, 239 and 74, this is what appears on the serial port: 87623974.