Question

The effect of mean monthly daily temperature and cost per kilowatthour x, on the mean daily household consumption of electricity (in kilowatt-hours, kWh) was the subject of a short-term study. The investigators expected the demand for electricity to rise in cold weather (due to heating), fall when the weather was moderate, and rise again when the temperature rose and there was need for air-conditioning. They expected demand to decrease as the cost per kilowatt-hour increased, reflecting greater attention to conservation. Data were available for 2 years, a period in which the cost per kilowatt-hour X, increased because of the increasing cost of fuel. The company fitted the model Ely) - Bo+B1*1 +Byx12 + B3*2 +B4*1*2 +B5*12x2 to the data shown in the table. The Excel printout for this multiple regression problem is also provided. Price per kWh, X Daily Temperature and Consumption Mean Daily Consumption (kWh) per Household 30 35 Mean daily temperature (°F), X1 Mean daily consumption, y Mean daily temperature, X1 10€ SO V Mean daily consumption, y 40 40 44 50 55 SUMMARY OUTPUT Regression Statistics Multiple R 0 .951 R Square 0.903 Adjusted R Square 0.877 Standard Error 2.852 Observations ANOVA F 33.693 Significance F 0.000 Regression Residual Total df 5 18 23 MS 274.044 8.134 ss 1370.221 146.404 1516.625 Intercept x1 x1-sq Coefficients 332.334 -11.707 0.117 -22.372 0.905 -0.009 Standard Errort Stat 80.768 4.115 3.155 -3.710 0.029 4.071 8.984 -2.490 0.350 2.587 0.003 -2.898 P Value 0.001 0.002 0.001 0.023 0.019 0.010 x1x2 xisqx2

Answer 1

1) from given o/p

value of F = 33.693

c)

F=22.88

rejection region, F>3.47 [excel function:"=F.INV.RT(0.05,2,21)"