{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

Problem Set 2 Solutions

Problem Set 2 Solutions - C hemistry 2101 I ntroductory...

Info icon This preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Chemistry 2101 Introductory Analytical Chemistry Fall 2009 Solutions Problem Set 2 Chapter 4 Problem 4-1 The larger the precision, the smaller the standard deviation. The accuracy and standard deviation are not necessarily related. Problem 4-2 0.683, 0.955, 0.997 Problem 4-3 (a) Mean = 1.52767 (b) Standard deviation = 0.00126 {note degrees of freedom: 8-1} Relative standard deviation (0. 00126/1.52767) x 100 = 0.0825% (c) μ = x ± t s n = 1.52793 ± 3.707 ( ) 0.00007 ( ) 7 = 1.52793 ± 0.00010 Problem 4-4 (a) The region around the measured mean in which the true mean is likely to lie is called the confidence interval. (b) A 95% confidence interval is necessarily larger than a 90% confidence interval. The only way to increase the probability of finding the true mean in the interval is to increase the size of the interval. Problem 4-5 mean = 108.6 standard deviation = 7.1 90% confidence interval = 108.6±6.8 Problem 4-6 s pooled = 0.0004 49 t = 2. 32 Because the calculated t is larger than the tabulated t (2.306), the difference is significant. Problem 4-9 For indicators 1 and 2: s pooled = 0.0018648 t = 15.60
Image of page 1

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern