"there are two types of error that can occur when making measurements: systematic and random error. how you correct the error depends on the type(s) of error present."

Systematic error can be corrected using calibration of the measurement instrument, while random error can be corrected using an average measurement from a set of measurements.

Explanation:

Random errors lead to fluctuations around the true value as a result of difficulty taking measurements, whereas systematic errors lead to predictable and consistent departures from the true value due to problems with the calibration of your equipment.

Systematic error can be corrected, by calibration of the measurement instrument. Calibration is simply a procedure where the result of measurement recorded by an instrument is compared with the measurement result of a standard value.

Random error can be corrected using an average measurement from a set of measurements or by Increasing sample size.

Trial 1 (20.61 mL HCl):  

⇒ 0.121 M

Trial 2 (20.06 mL HCl):  

⇒ 0.125 M

Trial 3 (19.67 mL HCl):  

⇒ 0.122 M

the answer for the next question, Compute the average concentration (molarity) of HCl for all three trials, is 0.123 M.

Explanation: