1. Replicate water samples are analyzed for water hardness with the following results; 70.65, 70.63, 70.64, and 70.21 ppm CaCO3. Calculate the mean, sample standard deviation, variance, %RSD, and 99% CI. (15 pts) 2. The following replicate molarities were obtained when standardizing a solution: 0.1067, 0.1071, 0.1066, and 0.1050. Apply the Q test to determine whether one of the data can be rejected at 95% confidence level. (5 pts) 3. A calibration curve for the colorimetric determination of phosphorous in urine is prepared by reacting standard solutions of phosphate with molybdenum (VI) and reducing the phosphomolybdic acid complex to produce the characteristic blue color. The following data were obtained: ppm P Absorbance 1.00 0.205 2.00 0.410 3.00 0.615 4.00 0.820 Urine sample 0.625 a) Determine the linear least-squares line (equation of the line); (5 pts) b) Calculate the phosphorous concentration in the urine sample. (5 pts)