The pH of water samples taken from Iligan Bay was determined. Calculate the pooled estimate of the standard deviation for the analysis, based from the following columns of data: Site No. of Samples measured pH Mean pH Sum of Squares of Deviation from the Mean 1 4 8.02, 8.09, 7.95, 7.98 8.01 0.0110 2 3 7.50, 7.65, 7.49 7.55 0.0161 3 3 8.25, 8.29, 8.20 8.25 0.0041

The pH of water samples taken from Iligan Bay was determined. Calculate the pooled estimate of the standard deviation for the analysis, based from the following columns of data: Site No. of Samples measured pH Mean pH Sum of Squares of Deviation from the Mean 1 4 8.02, 8.09, 7.95, 7.98 8.01 0.0110 2 3 7.50, 7.65, 7.49 7.55 0.0161 3 3 8.25, 8.29, 8.20 8.25 0.0041

Fundamentals Of Analytical Chemistry

9th Edition

ISBN:9781285640686

Author:Skoog

Publisher:Skoog

Chapter7: Statistical Data Treatment And Evaluation

Section: Chapter Questions

Problem 7.10QAP

See similar textbooks

Similar questions

The following data represented the concentration of ofloxacin present in chicken meat samples: 4.17, 4.40, 4.35, 4.35, 4.20, 4.16,4.20 and 4.17. Estimated the % relative standard deviation.
4. A new method for the determination of mercury in fish was tested against a N.I.S.T. standard to determine if there was any bias (determinate error) in the new technique. The N.I.S.T. standard fish sample was certified to contain 13.55 ppm Hg. The results of six analyses by the new method gave a mean value of 14.15 ppm and s.d. = 0.42 ppm. Does the new method give accurate results at the 95% confidence level?
An analytical determination for manganese in an aqueous solution on gives thefollowing replicate measurements in ppm as 12.1, 12.3, 12.2, 12.2, 12.4, 12.3, 12.2, 12.4,12.2, and 12.5. Determine the following;a) The range of the datab) The meanc) Mediand) Standard deviatione) Variancef) Relative standard deviation RSD (ppt)
The results in the table below were obtained from the analyses of Mg2+ content in an orange juice sample using a flame-AAS. Based on these results answer the following questions: (i) (ii) Replicate 1 2 3 4 Mg²+(ppm) 7.08 7.21 7.12 7.09 Calculate the mean, standard deviation and coefficient of variation (or %RSD) for the results obtained. If the certified value of the Mg2+ content of the apple juice sample is 7.45 ppm. What is the percentage of recovery for this analysis?
2. The following values were obtained from the calibration of a 10mL pipet 10.28, 9.99, 10.12, and 9.63 mL. Calculate the mean value and the standard deviation from the mean.
The student was supposed to measure the pH of a 0.1 M hydrochloric acid solution. For this purpose, he used a pH-meter and obtained the following results: 0.90, 0.93, 1.04, 1.02. Present the appropriate graphic and statistical elaboration of the performed analysis and confirm whether the applied pH-meter worked properly.
The researcher extracts a sample of well water and prepares it for TXRF analysis with a 10.00 mg/L V internal standard, like the calibration standards. The result produces SCa = 69297.81 and SV = 13481.2.Determine the concentration of Ca.
A clinical chemist obtained the following data for the alcohol content of a sample of blood: % C,H OH: o.084, 0.089, and o.079. Calculate the 95% confi- dence interval for the mean assuming that (a) the three results obtained are the only indication of the precision of the method and that (b), from previous
A standard method for analyzing aspirin tablets has a known variance of 20. A sample of 10 aspirin tablets is selected and analysed for the amount of aspirin using a modified method, yielding the following results: 254, 249, 252, 252, 249, 249, 250, 247, 251, 252. Determine whether the precision of the modified method is significantly different from that of the standard method at, alpha(a) = 0.10
(3) In a titration, the % analyte is computed from the following equation: Vol (titrant) x M (titrant) x MW (analyte) % analyte = x 100 Weight (sample) Calculate the absolute error in the % analyte from the following data. Vol (titrant)= 38.04 t 0.02 ml M (titrant) MW (analyte) = 74.116 t 0.005 mg/mmol Wt (sample) = 800.0 ± 0.2 mg = 0.1137 ± 0.0003 mmol/ml %3!
Analysis of several plant-food preparations for potassium ion yielded the following data: Sample Percent K+ 1 3.90, 3.96, 4.16, 3.96 2 4.48, 4.65, 4.68, 4.42 Find the mean ; standard deviation variance and RSD for each sample.
The following data was obtained when four bottles of wine, were analyzed for residual sugar content and the results obtained are the followingB Bottles % w/v Residual Sugar 1 0.97, 0.86, 1.02 2 1.25, 1.32, 1.13, 1.20, 1.12 3 0.9, 0.92, 0.73 0.72, 0.77, 0.61,0.58 a) For each set, determine the mean, spread, standard deviation s and coefficient of variation. b) Calculate the pooled standard deviation, spooled. 2.

SEE MORE QUESTIONS

Recommended textbooks for you

Fundamentals Of Analytical Chemistry

Chemistry

ISBN:

9781285640686

Author:

Skoog

Publisher:

Cengage

Principles of Instrumental Analysis

Chemistry

ISBN:

9781305577213

Author:

Douglas A. Skoog, F. James Holler, Stanley R. Crouch

Publisher:

Cengage Learning

Appl Of Ms Excel In Analytical Chemistry

Chemistry

ISBN:

9781285686691

Author:

Crouch

Publisher:

Cengage

Fundamentals Of Analytical Chemistry

Chemistry

ISBN:

9781285640686

Author:

Skoog

Publisher:

Cengage

Principles of Instrumental Analysis

Chemistry

ISBN:

9781305577213

Author:

Douglas A. Skoog, F. James Holler, Stanley R. Crouch

Publisher:

Cengage Learning

Appl Of Ms Excel In Analytical Chemistry

Chemistry

ISBN:

9781285686691

Author:

Crouch

Publisher:

Cengage

SEE MORE TEXTBOOKS

GET THE APP

About FAQ Academic Integrity Sitemap Document Sitemap

Contact Bartleby Contact Research (Essays)High School Textbooks Literature Guides Concept Explainers by Subject Essay Help Mobile App

GET THE APP

Privacy

Your CA Privacy Rights

Your NV Privacy Rights

About Ads

Manage My Data

bartleby, a Learneo, Inc. business

Site	No. of Samples measured	pH	Mean pH	Sum of Squares of Deviation from the Mean
1	4	8.02, 8.09, 7.95, 7.98	8.01	0.0110
2	3	7.50, 7.65, 7.49	7.55	0.0161
3	3	8.25, 8.29, 8.20	8.25	0.0041