The actual value = 25.7 ml The error = 15.6% This means that the value of error = 0.156 * 25.7 = 4.0092 ml
Now, the error percentage found means that the student got the value either greater than the actual one with the value of error or less than the actual one with the value of error.
This means that the two possible readings are: either : 25.7 + 4.0092 = 29.7092 ml or : 25.7 - 4.0092 = 21.6908 ml
To find what 15.6% of 25.7 is, multiply 25.7 by 15.6% in decimal form which is .156 25.7 x 0.156 = 3.9936 The answer to this is 25.7 plus or minus 3.9936 meaning your two possible values for the student's experiment are 29.4936 or 21.7064
