Using the given data create a standard curve in Excel, and use Trendline to add a linear regression with the equation. Then use the standard curve and the dilutions to determine the concentration ofNO₃^-in all the samples. Using the data analysis tool pack, perform the appropriate t-test to deduce if the nitrate concentration upslope is less than or greater than the nitrate concentration downslope. When performing a t-test using the data analysis tool pack, the output will include the means for both groups.

What is the averageNO₃^-concentration at the upslope site?

• Report your answer, from the data analysis toolpakoutput, to 3 decimal places

What is the averageNO₃^-concentration at the downslope site?

• Report your answer, from the data analysis tool pakoutput, to 3 decimal places

Given the EPA drinking water quality standard is 10 mg/L of nitrate, is the upslope site safe to drink based only on nitrate content?(Enteryesorno)

Is the downslope site safe to drink, based only onNO₃^-concentration?(Enteryesorno)

Assuming the two sites are hydrologically well connected, the transit time between the two sites is fast, and the two sites cannot be treated as independent samples, what kind of t-test should be performed to show that the upslope site is greater than the downslope site? Enter the letter of your answer choice in the answer blank

A. one-tailed unpaired t-test

B. two-tailed unpaired t-test

C. one-tailed paired t-test

D. two-tailed paired t-test

What is the calculated t statistic, rounded to 4 decimal places?

Is the calculated t statisticgreaterorlessthan the critical t value reported by the data analysis tool pack?(entergreaterorless)

Is the nitrate concentration at the upslope site significantly greater than the downslope site?(Enteryesorno)

Based on this statistical result, and assuming no diffusion or dilution occurs between the upslope and downslope site, do you think microbes are removingNO₃^-from the ground water?(Enteryesorno)

Standard ID mg N per L Abs Sample ID Upslope Absorbance Dilution Downslope Absorbance Dillution Std 0 0 0 1 0.5 0.01 mg N/L Upslope 0.2 0.5 Std 0.1 0.1 0.12 2 0.5 0.01 0.251 0.5 Std 0.2 0.2 0.225 3 0.395 0.01 0.951 1 Std 0.4 0.4 0.432 4 0.332 0.1 0.2 1 Std 0.6 0.6 0.585 5 0.551 0.01 0.149 1 6 0.556 0.01 0.2 0.5 7 0.359 0.02 0.251 1 8 0.331 0.01 0.2 1 9 0.363 0.01 0.951 0.5 10 0.244 0.02 0.159 1 11 0.375 0.01 0.2 0.5 12 0.5 0.02 0.143 0.5 13 0.541 0.1 0.317 1 14 0.669 0.01 0.563 1 15 0.328 0.1 0.925 0.5 16 0.417 0.01 0.563 1 17 0.449 0.02 0.653 1 18 0.5 0.01 0.915 0.5 19 0.642 0.1 0.167 1 20 0.5 0.01 0.148 1 21 0.243 0.1 0.851 0.5 22 0.375 0.01 0.536 1 23 0.5 0.02 0.941 0.5 24 0.868 0.1 0.159 0.5 25 0.119 0.01 0.897 0.5 26 0.459 0.01 0.316 0.5 27 0.532 0.02 0.313 0.5 28 0.686 0.01 0.458 1 29 0.5 0.02 0.331 0.5 30 0.206 0.01 0.797 1 mg N/L Downslope