oo Sprint 1002 PM moodle2Isuedu 6 of 7 Page 5 of 7 Revised 1

oo Sprint 10:02 PM moodle2.Isu.edu 6 of 7 Page 5 of 7 Revised 11/10/2010 6. (Question 6 subparts below) 6A. Forasignificance level 0.05, a P-value of 0.025 in an ANOVA means that the data give evidence that the means of all populations are equal . True False . It depends 6B, which population means can be considered significantly different in the Tukey Grouping shown below? 17.95 A 15.25 A B 12.80 A B 11.15 9.05 *1, 3 and 5 2 and 4 * 3 and S -1,2, 3 and 4 7. An engineer wants to know if the strengths of two separate concrete mixes are different. He randomly selects 9 cylinders of mixture 67-0-301 (sample #1) and 10 cylinders of mixture 67-0-400 (sample #2). After 28 days, he measures the strength (in pounds per square inch) of the 6 by 12 inch cylinders and obtains the information below. Use significance level 0.0S Box plot- all points inside fences Normal probability plot- all points inside bounds. Sample 67-0-301 67-0-400 9 3,669 458.5 2 10 4,483 473.7 7A. What is the appropriate test procedure? Two-sample z-test of the mean. Two-sample t-test of the mean. Two-sample z-test of proportion. . * Paired-sample t-test of the mean Page 6 of 7

Solution

We have here given sampes are n₁ = 9 and n₂  = 10.

i.e. n₁ < 30 and n₂  < 30

Therefore, Here we can use Two sample t test of mean.

Option B) is correct here.