Two students determine the percentage of lead in a sample as a laboratory exerci

Question

Two students determine the percentage of lead in a sample as a laboratory exercise. The true pew tage is 24.12%. The students' results for three determinations are as follows 124.18, 24.24, 24.21 2. 24.08, 24.11, 24.1 (a) Calculate the average percentage for each set of data, and state which set is the more accurate based on the average data set 1 data set 2 O Set 1 is more accurate. Set 2 is more accurate. O Both sets are equally accurate. (b) Precision can be judged by examining the average of the deviations from the average value for that data set (Calculate the average value for each data set; then caiculate the average value of the absolute deviations of each measurement from the average.) Which set is more precise to the hundredth place? data set 1 data set 2 Set 1 is more precise. Set 2 is more precise. Both sets are equally precise. e 46 4 5 6 7 8 9

Explanation / Answer

Part a

Average value

Data set 1 = (24.18 + 24.24 + 24.21)/3 = 24.21

Data set 2 = (24.08 + 24.11 + 24.14)/3 = 24.11

Data set 2 is more accurate because 24.11 is close to 24.12%

Part b

For data set 1

Absolute deviation from average

24.21 - 24.18 = 0.03

24.24 - 24.21 = 0.03

24.21 - 24.21 = 0.00

Average value of Absolute deviation from average

Data set 1 = (0.03 + 0.03 +0.00)/3 = 0.02 = 2*10^-2

For data set 2

Absolute deviation from average

24.11 - 24.08 = 0.03

24.11 - 24.11 = 0.00

24.14 - 24.11 = 0.03

Average value of Absolute deviation from average

Data set 2 = (0.03 + 0.00 +0.03)/3 = 0.02 = 2*10^-2

Both sets are equally precise

Related Questions

Navigate

• Browse (All)
• Browse T
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.