Answer:
Mean would be 100 instead of 125
Median would be 120 instead of 125
Explanation:
Mean is adding up all the given numbers and dividing them by number of numbers given. So (100+120+130+150)/4. But with adding 0, you would divide the number by 5 because that is adding one extra data number.
Median before is finding the number in the middle, which is both 120 and 130. You add those two values and divide by 2 to get median score if there isn't one definite number as the middle number. Adding 0 will give 120 the title for median.