The specific heat of water is 4.184 J/g·K. How much energy must be added to 100.0 g of water to raise the temperature of water from 22.0 ºC to 90.0 ºC? Select one:
a. 2.84 kJ
b. 136 J
c. 28.4 kJ
d. 6800 J

The chemical composition of soil varies with depth. an article in communications in soil science and plant analysis describes chemical analyses of soil taken from a farm in western australia. fifty specimens were each taken at depths 50 and 250 cm. at a depth of 50 cm, the average no3 concentration (in mg/l) was 88.5 with a standard deviation of 49.4. at a depth of 250 cm, the average concentration was 110.6 with a standard deviation of 51.5. find a 95% confidence interval for the difference in no3 concentrations at the two depths.