代做Introduction to Quantitative Methods Final EXAM代做Python编程
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45 Points
Question 1 (15 points)
Global warming is a major issue, and CO2 emissions are an important part of the discussion. What is the effect of increased CO2 levels on the environment? In particular, what is the effect of these higher levels on the growth of plants and trees? The article “Effects of Atmospheric CO2 Enrichment on Biomass Accumulation and Distribution in Eldarica Pine Trees” (J. Exp. Bot., 1994: 345–349) describes the results of growing pine trees with increasing levels of CO2 in the air. There were two trees at each of four levels of CO2 concentration, and the mass of each tree was measured after 11 months of the experiment. The table below shows the observations with x = atmospheric concentration of CO2 in microliters per liter (parts per million) and y = mass in kilograms, along with x2, xy andy2. The mass measurements were read from a graph in the article.
Obs. |
x |
y |
1 |
408 |
1.1 |
2 |
408 |
1.3 |
3 |
554 |
1.6 |
4 |
554 |
2.5 |
5 |
680 |
3.0 |
6 |
680 |
4.3 |
7 |
812 |
4.2 |
8 |
812 |
4.7 |
a). Estimate that the expected change in tree mass associated with a 1-part-permillion increase in CO2 concentration.
b). Write down the equation of the estimated regression line (least squares line)
Question 2 (15 points)
Two different companies have applied to provide cable television service in a region. Let p denote the proportion of all potential subscribers who favor the first company over the second. Consider testing H0: p = .5 versus Ha : p ≠ .5 based on a random sample of 25 individuals. Let X denote the number in the sample who favor the first company and x represent the observed value of X
a. Which of the following rejection regions is most appropriate and why? R1 = {x: x ≤ 7 or x ≥ 18};
R2 = {x : x ≤ 8}; R3 = {x : x ≥ 17}
b. In the context of this problem situation, describe what type I and type II errors are.
c. What is the probability distribution of the test statistic X when H0 is true? Use it to compute the probability of a type I error.
d. Compute the probability of a type II error for the selected region when p = .3, again when p = .4, and also for both p = .6 and p = .7.
e. Using the selected region, what would you conclude if 6 of the 25 queried favored company 1?
Question 3 (15 points)
In some locations, there is a strong association between concentrations of two different pollutants. The article “The Carbon Component of the Los Angeles Aerosol: Source Apportionment and Contributions to the Visibility Budget” (J. Air Pollution Contr. Fed., 1984: 643–650) reports the accompanying data on ozone concentration x (ppm) and secondary carbon concentration y (mg/m3).
x |
.066 |
.088 |
.120 |
.050 |
.162 |
.186 |
.057 |
.100 |
y |
4.6 |
11.6 |
9.5 |
6.3 |
13.8 |
15.4 |
2.5 |
11.8 |
x |
.112 |
.055 |
.154 |
.074 |
.111 |
.140 |
.071 |
.110 |
y |
8.0 |
7.0 |
20.6 |
16.6 |
9.2 |
17.9 |
2.8 |
13.0 |
Calculate the point estimate of the population correlation coefficient r between ozone concentration and secondary carbon concentration.