1.Accu-Copier, Inc., sells and service the Accu-500 copying machine. As part of its standard service contract, the company agrees to perform routine service on this copier. To obtain information about the time it takes to perform routine service, Accu-Copiers has collected data for 11 service calls. The data and excel output from fitting a least squares regression line to the data are given below.

1.Find the least square point estimates b₀ and b₁ on the output and report their value. Interpret b₀ and b₁. Does the interpretation of b₀ make practical sense? (Table 1)

2.Use the least squares line to compute a point estimate of the mean time to service four copiers and a point prediction of the time to service for copiers on a single call. (Table 1)

3. Find SSE and S (Table 1)

4.Find S_b1 and the t statistic for testing the significance of the slope on the output (table 1)

5.Find the p-value for testing Ho: ₁=0 versus Ha=₁0 on the output. Using the p-value, determine whether we can reject Ho by setting equal to 0.10, 0.05, 0.01 and 0.001. How much evidence is there that the slope (regression relationship) is significant? (Table 1)

6.Find the 95% confidence interval for ₁ on the output. (Table 1)

7.Find a point estimate of and a 95% confidence interval for the mean time to service four copiers. (Table 2)

8.Find a point prediction of and a 95% prediction interval for the time to service four copiers on a single call. (Table 2)

9.The residuals are plotted against the x in blow figure. Dis this figure indicate a volition of the normality assumption? Explain. (Figure 1)

Table 1 Excel Output for Service Time

SUMMARY OUTPUT

Regression Statistics Multiple R 0.995 R Square 0.990 Adjusted R Square 0.989 Standard Error 4.615 Observations 11 ANOVA of SS MS F Significance F Regression 19918.8438 19918.8438 935.1489 0.0000 Residual 191.7017 21.3002 1 Total 10 20110.5455 Coefficients Standard Error t Stat P-value Lower 95% Upper 95% Intercept 11.4641 3.4390 3.3335 0.0087 3.6845 19.2437 Copiers 24.6022 0.8045 30.5802 0.0000 22.7823 26.4221Table 2 Predicted values for y Predicted values for: Minutes (y) 95% Confidence Intervals95% Prediction Intervals Copiers (x) Predicted lower upper lower upper 36.066 29.907 42.226 23.944 48.188 2 60.669 55.980 65.357 49.224 72.113 3 85.271 81.715 88.827 74.241 96.300 4 109.873 106.721 113.025 98.967 120.779 5 134.475 130.753 138.197 123.391 145.559 6 159.077 154.139 164.016 147.528 170.627 7 183.680 177.233 190.126 171.410 195.950Figure 1 Service time residual plot Copiers Residual Plot 10 Residuals bakNONow 5 6 7 8 Copiers