A consumer buying cooperative tested the effective heating area of 20 different electric space heaters with different wattages.

I just need help with questions d. and e.

a. Compute the correlation between the wattage and heating area. Is there a direct or an indirect relationship? (Round your answer to 4 decimal places.)
ANSWER: The correlation of Wattage and Area is 0.0031. The link (relationship is direct.

b. Conduct a test of hypothesis to determine if it is reasonable that the coefficient is greater than zero. Use the 0.100 significance level. (Round intermediate calculations and final answer to 3 decimal places.)
H₀: ρ ≤ 0; H₁: ρ > 0 Reject H₀ if t > 1.330
ANSWER: t = 0.013

c. Develop the regression equation for effective heating based on wattage. (Negative value should be indicated by a minus sign. Round your answers to 3 decimal places.)
ANSWER: Do not reject H₀. It is not reasonable to say the population correlation is negative.

d. What heating area corresponds with a 1,500-watt heater? (Round your answers to 4 decimal places.)

ANSWER: The regression equation is: Area = 147.300 + 0.001 Wattage

d. What heating area corresponds with a 1,500-watt heater? (Round your answers to 4 decimal places.)

e. What is the 95% confidence interval of heating the area if the wattage is 1,500? (Round your answers to 4 decimal places.)

[ , ]

Heater Wattage Area

1 1,800 265

2 1,000 71

3 1,500 247

4 1500 107

5 1,500 118

6 2,000 222

7 1,500 208

8 1,250 187

9 1,000 280

10 1,750 46

11 1,750 118

12 1,000 142

13 1,750 66

14 1,000 242

15 1,250 111

16 1,000 261

17 1,750 58

18 1250 88

19 1,500 87

20 400 40

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