An ISU engineering statistics student project concerned y = glued wood joint strength (1b) for several wood types and glues. Below are some summary statistics for oak wood and three types of glue. Use this information in questions 4. and 5. below. white glue carpenter's glue cascamite glue n = 3 n, = 3 n3 = 3 y1 = 257.7 1b V2 = 234.3 1b V3 = 177.7 1b S = 5.7 1b S, = 3.2 1b $3 = 10.1 1b 4. An estimate of the standard deviation of joint strength for oak wood and any one of the three glue types useful for making confidence limits for linear combinations of means a) is 6.9 with 9 degrees of freedom. b) is 6.9 with 6 degrees of freedom. c) is 6.3 with 9 degrees of freedom. d) is 6.3 with 6 degrees of freedom. 2 5. Two-sided confidence limits for _ (M + /2 ) -/; provide a kind of comparison of cascamite to the other two glues and are of the form (Hint: Lab 9 Q8) a) 68.31t .Spooled (.58) b) 68.3+t . Spooled (.71) c) 68.31t . Spooled (.82) d) 68.3+t . Spooked (1.00)