1. Find the mean of the following measurements: 1.825 g, 1.867 g, 1,845 mg, 1.888 g.
2. Find the standard deviation of the following: 4.365 ml, 4.322 ml, 4.528 ml, 4.441 ml, 4.311 ml.
3. Find the standard deviation for c ( = a + b), if a = 7.123 mg (plus or minus 0.034 mg) and b = 5.239 (plus or minus 0.064 mg).
4. Find the standard deviation in area for a rectangular flange, if the the length is 5.236 cm (plus or minus 0.125 cm) and the width is 3.972 cm (plus or minus 0.191 cm).
5. Determine (at the 95% confidence level) if one of the following points should be discarded: 131.2 mg, 124.6 mg, 183.9 mg, 144.3 mg.
6. Soil removed from a murder suspect's shoes is tested for heavy metals. The % Pb is determined as 1.245 ppm, 1.543 ppm, 1.324 ppm, 1.477 ppm. If the true mean of Pb content at the soil at the murder scene is 1.62 ppm, do we have evidence of the suspect's guilt (at the 99% confidence limit)?
7. Ferrous hydroxide has a solubility product constant of 1 x 10-15. How many grams of ferrous hydroxide will dissolve in 500 ml of water?
8. What is the solubility of barium iodate in a solution that is 0.07 M NaIO3?
9. What is the strongest acid that can exist in water? The strongest base?
10. Suppose the standard deviation is equal to 0.210. How many measurements do we need to reduct the confidence interval to plus or minus 0.03 at the 95% confidence level?
© 2005 by Lawrence T. Sein. All rights reserved.
Send questions to:lseinjr@hotmail.com