Inorganic phosphorous is a naturally occurring element in all plants and animals, with concentrations increasing progressively up the food chain (fruit < vegetables < cereals < nuts < corpse). Geochemical surveys take soil samples to determine phosphorous content (in ppm, parts per million). A high phosphorous content may or may not indicate an ancient burial site, food storage site, or even a garbage dump. Independent random samples from two regions gave the following phosphorous measurements (in ppm). Assume the distribution of phosphorous is mound-shaped and symmetric for these two regions Region I: x1; n = 15 855 1550 1230 875 1080 2330 1850 1860 2340 1080 910 1130 1450 1260 1010 Region II: x2; n2 = 14 540 810 790 1230 1770 960 1650 860 890 640 1180 1160 1050 1020 (a) Use a calculator with mean and standard deviation keys to verify that x1, $1, X2, and s2. (Round your answers to one decimal place.) X1 = ppm S1 = ppm ppm ppm X2 = S2 = (b) Let µ1 be the population mean for x1 and let 42 be the population mean for x2. Find a 95% confidence interval for 41 - H2. (Round your answers to one decimal place.) lower limit ppm upper limit ppm (c) Explain what the confidence interval means in the context of this problem. Does the interval consist of numbers that are all positive? all negative? of different signs? At the 95% level of confidence, is one region more interesting than the other from a geochemical perspective? O Because the interval contains both positive and negative numbers, we can not say that one region is more interesting than the other. Because the interval contains only positive numbers, we can say that region I is more interesting than region II. O Because the interval contains only negative numbers, we can say that region II is more interesting than region I. We can not make any conclusions using this confidence interval. (d) Which distribution (standard normal or Student's t) did you use? Why? O Student'st was used because o, and oz are known. Student's t was used because og and az are unknown. O Standard normal was used because o, and oz are unknown. Standard normal was used because o and oz are known.

Trace metals in drinking water affect the flavor and an unusually high concentration can pose a health hazard. Ten pairs of data were taken measuring zinc concentration in bottom water and surface water. Bottom 0.430 0.266 0.567 0.531 0.707 0.716 0.651 0.589 0.469 0.723 Surface 0.415 0.238 0.390 0.410 0.605 0.609 0.632 0.523 0.411 0.612 With the help of Mathematics and R Studio: Does the data suggest that the true average concentration in the bottom water is different than that of surface water? You can assume that the conditions for inference are met.

Inorganic phosphorous is a naturally occurring element in all plants and animals, with concentrations increasing progressively up the food chain (fruit < vegetables < cereals < nuts < corpse). Geochemical surveys take soil samples to determine phosphorous content (in ppm, parts per million). A high phosphorous content may or may not indicate an ancient burial site, food storage site, or even a garbage dump. Independent random samples from two regions gave the following phosphorous measurements (in ppm). Assume the distribution of phosphorous is mound-shaped and symmetric for these two regions. Region I: x1; n1 = 15 853 1,549 1,230 875 1,080 2,330 1,850 1,860 2,340 1,080 910 1,130 1,450 1,260 1,010 Region II: x2; n2 = 14 538 808 790 1,230 1,770 960 1,650 860 890 640 1,180 1,160 1,050 1,020   (a) Use a calculator with mean and standard deviation keys to verify that x1, s1, x2, and s2. (Round your answers to four decimal places.) x1= ppm s1= ppm x2= ppm s2=…

The weight percent of silicon in six different rock samples, each containing different amounts of silicon, was measured by two different methods. The results are given in the table. Sample Method A Si wt% Method B Si wt% 1 11.570 11.500 2 15.380 15.300 3 17.950 17.830 4 22.840 22.810 5 25.110 25.150 6 27.070 27.040 Determine tcalc. tcalc = Determine ttable at the 95% confidence level. A list of t values can be found in the Student's t table. ttable =

Inorganic phosphorous is a naturally occurring element in all plants and animals, with concentrations increasing progressively up the food chain (fruit < vegetables < cereaise nuts < corpse). Geochemical surveys take soil samples to determine phosphorous content (in ppm, parts per million). A high phosphorous content may or may not indicate an ancient burial site, food storage site, or even a garbage dump. Independent random samples from two regions gave the following phosphorous measurements (in ppm). Assume the distribution of phosphorous is mound-shaped and symmetric for these two regions. Region It x n, 15 857 1,551 1,230 875 1,080 2,330 1,850 1,860 2,340 1,080 910 1,130 1,450 1,260 1,010 Region III xi n 14 542 B06 1,230 1,770 790 960 1,650 860 890 640 1,180 1,160 1,050 1,020 A USE SALT (a) Use a caiculator with mean and standard deviation keys to verify that a and s (Round your answers to four decimal places.) ppm ppm ppm ppm (b) Let , be the population mean for x, and let be the…

Inorganic phosphorous is a naturally occurring element in all plants and animals, with concentrations increasing progressively up the food chain (fruit < vegetables < cereals < nuts < corpse). Geochemical surveys take soil samples to determine phosphorous content (in ppm, parts per million). A high phosphorous content may or may not indicate an ancient burial site, food storage site, or even a garbage dump. Independent random samples from two regions gave the following phosphorous measurements (in ppm). Assume the distribution of phosphorous is mound-shaped and symmetric for these two regions. Region I: x1; n1 = 15 857 1,551 1,230 875 1,080 2,330 1,850 1,860 2,340 1,080 910 1,130 1,450 1,260 1,010 Region II: x2; n2 = 14 538 808 790 1,230 1,770 960 1,650 860 890 640 1,180 1,160 1,050 1,020   (a) Use a calculator with mean and standard deviation keys to verify that x1, s1, x2, and s2. (Round your answers to four decimal places.) x1= 1387.5333 ppm s1=…

A geologist collects hand-specimen sized pieces of limestone from a particular area. A qualitative assessment of both texture and color is made with the following results. Is there evidence of association between color and texture for these limestones? Explain your answer.     Color   Texture Light Medium Dark Fine 7 15 4 Medium 5 18 15 Coarse 17 29 5

Inorganic phosphorous is a naturally occurring element in all plants and animals, with concentrations increasing progressively up the food chain (fruit < vegetables < cereals < nuts < corpse). Geochemical surveys take soil samples to determine phosphorous content (in ppm, parts per million). A high phosphorous content may or may not indicate an ancient burial site, food storage site, or even a garbage dump. Independent random samples from two regions gave the following phosphorous measurements (in ppm). Assume the distribution of phosphorous is mound-shaped and symmetric for these two regions Region I: x1; n1 = 15 855 1550 1230 875 1080 2330 1850 1860 2340 1080 910 1130 1450 1260 1010 Region II: x2; n2 = 14 540 810 790 1230 1770 960 1650 860 890 640 1180 1160 1050 1020 (a) Use a calculator with mean and standard deviation keys to verify that x1, s1, x2, and s2. (Round your answers to one decimal place.) x1 = ppm s1 = ppm x2 = ppm s2 = ppm (b)…

rofessor Cornish studied rainfall cycles and sunspot cycles. (Reference: Australian Journal of Physics, Vol. 7, pp. 334-346.) Part of the data include amount of rain (in mm) for 6-day intervals. The following data give rain amounts for consecutive 6-day intervals at Adelaide, South Australia. 7 28 7 1 69 3 1 4 22 7 16 4 54 160 60 73 27 3 3 1 7 144 107 4 91 44 1 8 4 22 4 59 116 52 4 155 42 24 11 43 3 24 19 74 26 63 110 39 34 71 52 39 8 0 15 2 14 9 1 2 4 9 6 10 (i) Find the median. (Use 1 decimal place.)(ii) Convert this sequence of numbers to a sequence of symbols A and B, where A indicates a value above the median and B a value below the median. Test the sequence for randomness about the median at the 5% level of significance. (b) Find the number of runs R, n1, and n2. Let n1 = number of values above the median and n2 = number of values below the median. R   n1   n2   (c) In the case, n1 > 20, we cannot use Table 10 of Appendix II to find the critical…

Analysis of several plant-food preparations for potassium ion yielded the following data:   Sample Percent K+ 1 6.02, 6.04, 5.88, 6.06, 5.82 2 7.48, 7.47, 7.29 3 3.90, 3.96, 4.16, 3.96 4 4.48, 4.65, 4.68, 4.42 5 5.29, 5.13, 5.14, 5.28, 5.20   The preparations were randomly drawn from the same population. a. Find the mean and standard deviation s for each sample b. Obtain the pooled value spooled c.Why is spooled a better estimate of s than the standard deviation from any one sample?