Mariana and Felix were in science class and were using a test kit to measure the amount of calcium in milk. They measured the amount of calcium in $1$ cup of milk $10$ times and got a mean of $294.6$ mg. They looked up the amount of calcium that is typically in milk and found out it was $290$ mg per $1$ cup. Percent error finds the difference between the actual value and measured value and the compares that difference to the actual value as a percentage. Find the percent error of Mariana and Felix’s measurement.