Purchase Solution

95% Confidence Level and Systematic Error

Not what you're looking for?

Ask Custom Question

We are using the book Analytical Chemistry 7th edition by Skoog, West, Holler, and Crouch

This question requires all equations to be written out. Thanks so much!

To test the quality of work of a commercial laboratory, 15 replicate analyses of a purified benzoic acid (68.8% C, 4.953%H) sample were requested. The absolute standard deviation of the method is s=4ppt for carbon and s=6ppt for hydrogen. The means of the reported results are 68.5% C and 4.882% H. At the 95% confidence level, is there any indication of systematic error in either analysis?

for 95% confidence the degrees of freedom are as follows:

Number of observatoins 95% Confidence
3 0.970
4 0.829
5 0.710
6 0.625
7 0.568
8 0.526

I don't remember if you subtract the total results by 1 or not for this question.

Don't know if you need this or not

Degrees of Freedom Factor for Confidence Interval95%
1 12.7
2 4.30
3 3.18
4 2.78
5 2.57
6 2.45
7 2.36
8 2.31
9 2.26
10 2.23
11 2.20
12 2.18
13 2.16
14 2.14

Purchase this Solution

Purchase this Solution

Free BrainMass Quizzes

The quiz helps in revising basic concepts about thermochemistry.

Match Elements with their Symbols

Elements are provided: choose the matching one- or two-letter symbol for each element.

General Chemistry - Classification of Matter

This test will assess your knowledge on the classification of matter which includes elements, compounds and mixtures.

Organic Chemistry Naming: Alkanes

This is a quiz which is designed to assist students with learning the nomenclature used to identify organic compounds. This quiz focuses on the organic compounds called Alkanes.