Calculate the mean and standard deviation for the following results for the concentration of lead in a soil sample. 23.2 ppm, 20.1 ppm, 24.7 ppm, 19.9 ppm, 21.8 ppm ○ 27.4±4.2 (n = 5) ppm O 21.9 ± 2.0 (n =5) ppm O 21.9±3.4 (n = 5) ppm O 22.0 ± 1.8 (n = 5) ppm O 27.4±2.0 (n = 5) ppm

Analysis of Results1. Summarize you Hardness results.2. Does the hardness of your sample fall within the expected range?3. How would the water be classified in terms of hardness (soft, moderately hard, hard, etc.)?

Homework 4: A dry rock sample of a weight equal to 1350 gm and a diameter of 7.5 cm and a height equal to twice the length. If you know that the size of the voids inside the rock is 180 cm³, find the following: Moisture content, real specific weight of the rock, percentage of voids, dry density, degree of saturation, air content. [Ans: o=0, G₁=2.797, e-0.373, ya-2.04 g/cm³, S,=0 and a. 1]

Tina 20 Two soil specimens with identical geometric dimensions were subjected to falling head permeability tests in the laboratory under identical conditions. The fall of water head was measured after an identical time interval. The ratio of initial to final water heads for the test involving the first specimen was 1.25. If the coefficient of permeability of the second specimen in 5 times that of the first, the ratio of initial to final water heads in the test involving the second specimen is