Unformatted text preview: 15. In ANOVA, the total amount of variation within samples is measured by:
a. the grand mean ‘ L b. the mean squares for treatments c. the mean squares for error d. the sum of squares for error e. the sum of squares for treatments Use the following information to answer the next 2 questions (16—17): A governmental organization was interested in measuring the effect of schooling on mental ability of students,
so they designed a particular IQ test for elementary students. The test was performed on a group of students
right before school started in the fall (after a long and lazy summer). The population standard deviation on
this IQ test is assumed to be 10 points. With a random sample of 75 students, the sample mean is found to
be 103 with a sample standard deviation of 20 points. Can the researchers conclude that summer break has
increased the variance in scores? 16. What are the appropriate null and alternative hypotheses for the researchers question?
a. H0202=0vs.H12027é0 b. H0:a2=400 vs. H1:027é400
c. H0:(72=100 vs. H1:0'27E100
d. H0:0'2 :400 vs. H1 : 02 >400
e. H0:02=100vs. H1202>100 17. What is the value of the lower 95% conﬁdence interval for the researchers question? 363025.75 = 100-839 X30535 = 96-217 96397535 2 52-942 X33535 = ”6-054
X3.o25,74 : 99-678 X335,“ = 95-081 X3975,“ = 52-103 X33534 = 55-189 . 74.2390
. 311.3135 ...
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- Fall '08