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

Heater	Wattage	Area
1	750		168
2	750		58
3	1,500		56
4	750		51
5	1,000		237
6	1,250		105
7	1,000		139
8	2,000		197
9	1,250		80
10	1,500		166
11	750		75
12	1,750		292
13	2,000		49
14	1,250		78
15	1,750		269
16	750		162
17	1,250		171
18	1,500		147
19	2,000		244
20	1,000		73

Required: 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.)

b. Conduct a test of hypothesis to determine if it is reasonable that the coefficient is greater than zero. Use the 0.050 significance level. (Round intermediate calculations and final answer to 3 decimal places.) H₀: 0; H₁: > 0 Reject H₀ if t > 1.734

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.)

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.)

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