The decline of water supplies in certain areas of the United States has created
ID: 3257168 • Letter: T
Question
The decline of water supplies in certain areas of the United States has created the need for increased understanding of relationships between economic factors such as crop yield and hydrologic and soil factors. An article gives data on grain sorghum yield (y, in g/m-row) and distance upslope (x, in m) on a sloping watershed. Selected observations are given in the accompanying table.
- Calculate the test statistic and determine the P-value. (Round your test statistic to two decimal places and your P-value to three decimal places.)
- Estimate true average yield when distance upslope is 75 by giving a 95% confidence interval. (Round your answers to one decimal place.)
x 0 10 20 30 45 50 70 80 100 120 140 160 170 190 y 500 585 410 465 450 475 510 445 360 405 300 415 280 345Explanation / Answer
Answer:
The decline of water supplies in certain areas of the United States has created the need for increased understanding of relationships between economic factors such as crop yield and hydrologic and soil factors. An article gives data on grain sorghum yield (y, in g/m-row) and distance upslope (x, in m) on a sloping watershed. Selected observations are given in the accompanying table.
x
0
10
20
30
45
50
70
80
100
120
140
160
170
190
y
500
585
410
465
450
475
510
445
360
405
300
415
280
345
- Calculate the test statistic and determine the P-value. (Round your test statistic to two decimal places and your P-value to three decimal places.)
test statistic F=18.96 and the P-value =0.0009
- Estimate true average yield when distance upslope is 75 by giving a 95% confidence interval. (Round your answers to one decimal place.)
Estimated true average=434.7
95% CI=(402.6, 466.8)
Regression Analysis
r²
0.612
n
14
r
-0.783
k
1
Std. Error
54.388
Dep. Var.
y
ANOVA table
Source
SS
df
MS
F
p-value
Regression
56,076.7512
1
56,076.7512
18.96
.0009
Residual
35,496.4631
12
2,958.0386
Total
91,573.2143
13
Regression output
confidence interval
variables
coefficients
std. error
t (df=12)
p-value
95% lower
95% upper
Intercept
512.9468
24.9522
20.557
1.01E-10
458.5808
567.3129
x
-1.0433
0.2396
-4.354
.0009
-1.5653
-0.5212
Predicted values for: y
95% Confidence Interval
95% Prediction Interval
x
Predicted
lower
upper
lower
upper
Leverage
75
434.703
402.634
466.771
311.939
557.466
0.073
x
0
10
20
30
45
50
70
80
100
120
140
160
170
190
y
500
585
410
465
450
475
510
445
360
405
300
415
280
345
Related Questions
drjack9650@gmail.com
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.