A group of researchers studied the effect of acid rain on wildlife and collected n = 12 samples from streams in different States. They recorded the pH (X) of the water (i.e. units above pH 7), and the BCI, a measure of biological diversity (Y). The data obtained is summarized below. DATA: Observation 1 2 3 4 5 6 7 8 9 10 11 12 pH above 7 (X) 0.65 0.50 0.93 0.86 1.02 0.94 1.16 1.24 1.30 1.45 1.85 1.89 Units of BCI (Y) 14.5 22.9 15.8 38.3 18.9 20.0 21.4 23.8 23.6 25.2 27.3 29.4

An engineer who accidentally inhaled poisonous fumes was given treatment for it. The concentration of poison in the engineer's blood was measured every hour. The table below shows the record: Hours Since Inhal ati on 1 5 Concentration 38.1 31.2 28.6 26.9 25.4 ug/ cm) The data in the table can be modelled by h = a +b lIn C, where h is the number of hours since the accident and C is the concentration of poison in the blood. If the engineer is allowed to return to work when the concentration of poison falls below 0.2, how many days must they wait to return to work? (Round your answer UP to the nearest day). Answer: 3. 2.

Mercury is a persistent and dispersive environmental contaminant found in many ecosystems around the world. When released as an industrial by-product, it often finds its way into aquatic systems where it can have deleterious effects on various avian and aquatic species. The accompanying data on blood mercury concentration (µg/g) for adult females near contaminated rivers in a state was read from a graph in an article. 0.20 0.23 0.24 0.30 0.35 0.41 0.54 0.57 1.43 1.70 1.82 2.20 2.24 3.08 3.24   (a) Determine the values of the sample mean and sample median.    Hint:          xi = 18.55.    (Round your answers to four decimal places.) x== Explain why they are different. The sample mean and sample median are never equal.They aren't different since the data is symmetric.    There is heavy negative skewness in the data.There are an odd number of data values.There is heavy positive skewness in the data. (b) Determine the value of the 10% trimmed mean.…

The efficiency for a steel specimen immersed in a phosphating tank is the weight of the phosphate coating divided by the metal loss (both in mg/ft2). An article gave the accompanying data on tank temperature (x) and efficiency ratio (y). Temp. Ratio Ratio 173 Temp. 183 0.76 Ratio 175 1.29 1.38 183 Temp. 185 185 176 USE SALT 183 185 1.87 2.04 2.70 177 1.51 1.70 1.65 2.21 2.07 0.99 X 177 183 183 187 1.01 0.98 178 187 184 179 188 1.06 184 0.74 1.47 189 180 1.82 185 0.92 191 1.59 2.42 2.92 1.95 3.14 (a) Determine the equation of the estimated regression line. (Round all numerical values to four decimal places.) y = 16.6666 + 0.1005x I X ÷ VO mathPa Operatio Function Symbols Relation Sets