In a NIST reference steel sample the certified percentage of nickel is 1.12% and the standard deviation related to this 0.03%. The determination of percentage produce for the nickel using new spectrometric method is − 1.10, 1.08, 1.09, 1.12 and 1.09. The indication of the bias in the method at the 95% level is to be determined. Concept introduction: The formula that will be used- C I , μ = x ¯ ± t s N Here, N = degree of freedom μ = confidence interval x ¯ = mean s = standard deviation t = constant

Question

A solution is prepared by weighing 5.0000 g of cesium iodide into a 100-mL volumetric flask. The balance used has a precision of 0.2 mg reported as a standard deviation, and the volumetric flask could be filled with a precision of 0.15mL also reported as a standard deviation. What is the estimated standard deviation of concentration (g/mL)?

Answer 1

Question

Chapter A1, Problem A1.16QAP

Interpretation Introduction

Interpretation:

In a NIST reference steel sample the certified percentage of nickel is 1.12% and the standard deviation related to this 0.03%. The determination of percentage produce for the nickel using new spectrometric method is − 1.10, 1.08, 1.09, 1.12 and 1.09. The indication of the bias in the method at the 95% level is to be determined.

Concept introduction:

The formula that will be used-

CI,μ=x¯±tsN

Here,

N = degree of freedom

μ = confidence interval

x¯ = mean

s = standard deviation

t = constant

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