Question

8. We want to predict the length of an icicle from the time it is allowed to grow. Utilize the attached Excel output, which contains the data for these icicles, to answer the following questions. a) (10 pts.) Give the least squares line and interpret the coefficients in terms of the original problem. b) (14 pts. Perform a test to see if the length of the icicle increases as the time increases by one. Use a = 0.05. c) (10 pts.) Find a 90% confidence interval for the change in the average length of the icicle when the time increases by 1.

sorry here it is

Answer 1

Time, ie independent variable length of an icicle ire dependent variable know that the least square regssion-line for prediction is, Ý = Båt Bix where, Bo is the estimate of the estimate of y-intercept of regression tine, slope of regression line given that, 86 - - 2151318 Bi= 0o 15982 : - 2 171 8 + c/S982 x # Interpretatgons O slope (B) : As the value of time increases (or changes) by one unit then the length of an ¿ cicle increases by 0-15982 (or increase ) mean ☺ y-intercept (po) : I Î the range of data on includes X20, then the intercept Po is the of the distribution of response y If the range of a does not include zero, then Bo has no practical interpretation. (ь То test, Ho: 8,0 Hii B, 0 CS

Page No. Date Test statistica tal= pino s. eepi) Ntn-2, Under Ho. secki) : 0.00362 BT: -0.15982 ... trala 0 15982 0.00362 ni tcal = 44.13. Here, p-value < 0.000) i e for significance level (2)=0.05 & p-value < 0.05 - we reject Ho at 5% level of significance conclusion : There is ARO significant relationship between time and length of an icicle .i.e the the length of the icicle increases as the time Increases one. for 1 1 Here, we have to consfouct 90%. C-J. the change in the average length of the icicle when the time increases by 1: i-e for B Inow that, a for Bi is P? 7 tahl2, 0-2 secp) Here, n=18 26.90 CS

in td/218-2= tolo , 18 = 1.7459 the required blis. co 0.15982 F 1.7459 x 0.00362 ( 0.1535, 601661 ) CS scanned with strat