Arduino altitude BMP 180. For loop help

Hey guys so essentially what im trying to do is store the altitudes in an array where i can access the numbers. Let me see if i can clarify that, so the arduino gives me relative altitudes on intervals(delay of what i choose for this example delay(1000)) of a second. The numbers look like
-.17
.10
-.24
.20
.18
-.09

etc etc So theres a considerable amount of noise in the detector. I want to store the values that it reads out in an array or something so i can add all those values up take the average and display that. But i cant figure out how to do that. i tried doing
for(i = 0; i <10;i++)
{
alt1 = a;
}
then when i print it using
for(i = 0; i <10; i++)
{
Serial.print(" ");
Serial.print(alt1*);*
Serial.print("\n\n");
}
i get something like this
Relative altitude is : -.24
-.24
-.24
-.24
-.24
-.24
-.24
-.24
-.24
-.24
-.24
So the for loop is being populated but by the same reading. I want it to store the reoccuring measurements. So that the loop could be something like
-.24
-.36
.89
so on and so forth. From there i would add the index’s together then take the average. But im completely lost.

If the most recent reading is the same as the last reading, don't store it.

An array is declared like this:int alt[10]; You write in the array like this:alt[i] = currentAltitude; You read an array like this:Serial.println(alt[i]);

Jacques