Project 2 - Measuring the distance of an object using ultrasonic sensor and also smoothen the sensor data using moving average filter

int trigpin = 11;
int echopin= 12;
long duration, cm, inches;
long sum=0;
long avg;
int i;

void setup()
{
serialEventRun(9600);
pinMode(trigpin,OUTPUT);
pinMode(echopin,INPUT);
}
void loop()
{
digitalWrite(trigpin,LOW);
delayMicroseconds(5);
delay(trigpin,HIGH);
delayMicroseconds(10);
digitalWrite(trigpin,LOW);
pinMode(echopin,INPUT);
duration=pulseIn(echopin,HIGH);
cm = (duration/2)29.1
inches = (duration/2)74
{
for(i==0,i<5,i++)
}
{
sum=sum+inches;
avg=sum/5;
}

Serial.print(avg);
Serial.print("Avg");
Serial.print(cm);
Serial.print("cm");
Serial.println();
Serial.print(inches);
Serial.print("in");
Serial.println();

delay(250);

}