Question

A customer service departments its customers to rate their over the phone service on a scale of 1-20 inediately after the service has been completed. The department the matches each customers in the number of minutes the person wahedon hol. The companying the shows the ratings and number of minutes on hold for 10 randomly testomers. The regression in the data iný 18.30-0. Use this mattis complete parts a tough mm Click the icon to view the table showing ratings and number of minutes on hold for 10 customers The p-value is 0.167(Round to three decimal places as needed) Because the value is greater than do not reject the null hypothes There is not enough evidence to conclude that the coefficient of termination is grant G. Construct a confidence interval for the average rating given by a customer who waits 18 minutes UCL (Round to two decimal places as needed) (Round to two decimal places as needed) L.

Answer 1

Here n= 10 X y X-X y-ý (x-x)? (y-y)? (x-x)(y-7) Ў Residual = y-) (y-9) 4 15 -1.0000 0.3000 1.0000 0.0900 -0.3000 15.1459 -0.1459 0.0213 8 13 3.0000 -1.7000 9.0000 2.8900 -5.1000 13.3622 0.1312 -0.3622 0.5162 1 17 16.0000 5.2900 -9.2000 16.4838 -4.0000 0.0000 2.3000 -4.7000 0.2665 22.0900 5 10 0.0000 22.0900 0.0000 14.7000 -4.7000 5 13 0.0000 -1.7000 0.0000 2.8900 -1.7000 2.8900 0.0000 -2.6000 14.7000 15.5919 3 16 -2.0000 1.3000 4.0000 1.6900 0.4081 0.1666 10 15 5.0000 25.0000 0.0900 1.5000 2.5297 12.4703 16.0378 6.3995 15.6987 2 0.3000 5.3000 -0.7000 20 -3.0000 9.0000 28.0900 -15.9000 3.9622 8 14 9.0000 0.4900 -2.1000 0.6378 3.0000 -1.0000 13.3622 15.1459 4 14 -0.7000 0.7000 -1.1459 1.0000 74.0000 0.4900 64.1000 0.4068 1.3132 49.3838 Total 50 147 -33.0000 147.0000 SST SSE =(x)/n = (50/10) = 5 y =(Ey)/n = (147/10) = 14.7

b= Σ(x – 3)(x-5). Σ(r-s)? -33/74 = -0.446

SSE Standard Error of estimate = Se = = 2.484547 Vn-2 Se Standard Error for Slope =S = 0.288823 2 (x-x

Degrees of freedom = n-2 = 8 Confidence Level = 95 Significance Level = a = (100-95)% = 0.05 Critical value = t* = 2.306 (using Excel =TINV(0.05,8)] 95% Confidence Interval for slope: Lower limit = b-t* (standard error for slope) = -1.11 Upper limit = b+t* (standard error for slope) = 0.22