Question

Data set 1 has coffee exports (thousands of 60-kilo bags) for December 2000 and total exports for 2001 for 42 coffee exporting countries excluding the three largest exporters (Brazil, Colombia, and Vietnam). A scatterplot is shown below.

Commodity traders would like to use December export figures from a particular country to predict total exports from that country in the coming year.

a) Use the data to come up with an equation for predicting total 2001 exports from December 2000 exports.

b) Assume that the equation you found in part “a” will apply to any year. If the coffee export of a country in December is 100, within what range would we expect to find the total exports for that country to fall in the coming year.

Total 2001 Exports 5000.00 4000.00 3000.00 2000.00 1000.00- 0.00 * 0.00 100.00 200.00 300.00 400.00 Dec 2000 Exports

Answer 1

(first part)2001exports(y)=102.0316+13.7220*2000exports(x)

here dependent variable y=2001exports and independent variable x=2000exports

(second part) expected range would be 1322.29 to 1626.17

for x=100, y=102.0316+13.7220*100=1474.2316

95% confidence interval=1474.23$\pm$2.021*490.4899*sqrt(1/49+(100-65.49)*(100-65.49)/386007)=1474.23$\pm$151.94=

(1322.29, 1626.17)

Confidence interval for the conditional mean of the response variable corresponding to S.x with df n -2 W1

following regression analysis information has been generated using ms-excel

SUMMARY OUTPUT
Regression Statistics
Multiple R	0.930698582
R Square	0.866199851
Adjusted R Square	0.862854848
Standard Error	490.4898924
Observations	42
ANOVA
	df	SS	MS	F	Significance F
Regression	1	62299079	62299079	258.9533	4.54E-19
Residual	40	9623213	240580.3
Total	41	71922292
	Coefficients	Standard Error	t Stat	P-value	Lower 95%	Upper 95%
Intercept	102.0315924	94.10681	1.08421	0.284763	-88.1654	292.2286
X Variable 1	13.72197913	0.852719	16.09203	4.54E-19	11.99857	15.44539

following data has been used for the analysis, please check as it was supplied in image form

year2000	year2001
0	180.3
0	1.83
0.13	3.39
0.3	3.01
0.76	193.05
1	11
1.09	26.31
1.43	34.16
2.09	29.47
2.45	17.25
3.15	93.64
4.26	82.49
4.58	106.44
5.37	294.6
7	124.63
8	73
8.34	47.68
9.27	63.71
9.88	109.23
10.68	1169.71
15.87	56.93
20.1	99.53
23.37	199.33
29.77	1167.08
32.55	294.83
41.06	303.18
58.66	1079.98
70.49	754.29
72.83	1364.59
77.66	1390.99
97.65	982.44
102.36	866.16
118.9	1521.64
128.99	2054.66
140.78	3964.27
152.49	2396
175.98	3521.39
176.98	2391.61
232.43	3053.3
260.72	4439.59
318.31	3408.33
326.98	4110.38