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1. T-tests compare __ averages. a. 2 b. 3 c. 4 d. 5 2. T-tests give the probabil

ID: 2932613 • Letter: 1

Question

1. T-tests compare __ averages.
a. 2
b. 3
c. 4
d. 5
2. T-tests give the probability that the differences are caused by __.
a. design
b. chance
c. cicumstances
d. the data
3. It is usually said that if the probability is less than __, than the difference is "significant."
a. 0.55
b. 0.5
c. 0.01
d. 0.05
4. Group A scores are 10,10,12,15,16 and group B scores are 9, 9, 14, 16, 17. You do the unpaired t-test. The t-est is ___.
a. 0.0235
b. 0.1894
c. 0.8523
d. 1.8892
5. Data as in Q4. Degrees of freedom is ___.
a. 2
b. 4
c. 6
d. 8
6. Data as in Q4. The standard error of diviation is ____.
a. 2.112
b. 3.668
c. 3.889
d. 6.222
7. Data as in Q4. The two means are ___.
a. 12.60
b. 14.98
c. 13.01
d. a and c
8. Data as in Q4. The standards of deviation are ___.
a. 3.66 and 5.66
b. 2.79 and 3.81
c. 3.11 and 4.67
d. 1.22 ans 2.56
9. Data as in Q4 and two taied P value of .084545 make it ___ statisitically significant..
a. very
b. a little
c. not
d. sometimes
10. You use a paired test when the scores are ___.
a. matched
b. unmatched
c. random
d. even
11. Data as in Q4. For the paired test, t = ____.
a. 0.5623
b. 0.6667
c. 1.5654
d. 2.4532
12. Data as in Q4. Paired test. df= ___.
a. 2
b. 4
c. 6
d. 8
13. The paired t-test of Q4 is statistically ___.
a. significant
b. insignificant
c. correct
d. meaningful
14. The t-test is the same as ___.
a. correlation
b. regression
c. ABOVA
d. nothing above
15. The t-value will be positive if the first mean is larger than the second, and negative if it is smaller. The rule of thumb is to set the alpha (risk) level at ___.
a. 0.2
b. 0.3
c. 0.4
d. 0.5
16. In the t-test, the degree of freedom is the sum of the persons in both groups minus ___.
a. 1
b. 2
c. 3
d. 4
17. The t-test employs that statistic (t) to test a given statistical hypothesis about the ___ of a population (or about the means of 2 populations.)
a. SD
b. mean
c. degrees of freedom
d. data
18. The Standard ____ of the mean is an estimate of the SD of the sample distribution of means, based on one more random samples
a. data
b. deviation
c. score
d. error
19. A statistical test of hypothesis is referred to as a ___-sample t-test.
a. one
b. two
c. three
d. four
20. In practive, the two-sample t-test is a more commonly used statistic. This statistic can evaluate whether or not there is a significant difference in the means of ___ independently sampled populations
a. 1
b. 2
c. 3
d. 4
21. A ____ sample binomial test allows us to test whether the proportion of successes on a two-level categorical dependent variable significantly differs from the hypothesized value.
a. 1
b. 2
c. 3
d. 4
22. t-tests concern a number of procedures dealing with the comparing of two averages. It can be used to compare the number of traffic accidents on two busy junctions.
a. true
b. false
c. sometime true
d. sometimes false
23. The formula for the t-test is a ___.
a. number
b. ratio
c. proportion
d. all of the above
24. The paired t-test compares ___ paired groups.
a. 1
b. 2
c. 3
d. 4
25. Group A is 8,5,7,2,4,5 and Group B is 9,6,5,3,3,6. The Paried t-test is
a. 0.4434
b. 0.4152
c. 0.5443
d. 0.6445
26. Data from Q25. df= ___.
a. 2
b. 3
c. 4
d. 5
27. Data from Q25. The M of Group A is __.
a. 5.0
b. 5.17
c. 5.33
d. 5.89
28. The ___ value answers this question. If the treatment really had no affect, what is the chance that random sampling would result in an average effect as far from zero (or more so) as observed in this experiment.
a. A
b. M
c. P
d. X
29. To compare ___ or more matched groups, use repeated measures one way ANOVA followed by post tests.
a. 1
b. 2
c. 3
d. 4
30. You can by ___% sure that this interval contains the true treatment effect. When the P value is larger than 0.05, the 95 confidence interval will start with a negative number.
a. 80
b. 85
c. 90
d. 95
31. If the t ratio is large, the P value will be ___.
a. large
b. unclear
c. disputed
d. small
32. Data from Q25. The two-tailed P value equals 0.6952. By conventional criteria, this difference is considered to be ___statistically significant.
a. some
b. always
c. not
d. very
33. In general, the ___ hypothesis is the logical antithesis of whatever hypothesis it is the investigator is seeking to examine.
a. real
b. opposite
c. null
d. calculated
34. Usually, the null hypothesis is that the difference is __.
a. 0
b. 1
c. 2
d. 3
35. The null hypothesis is put forward to allow the data to ___ it.
a. explain
b. agree with
c. proof
d. contradict
36. The result of the t-test is a t value, this value is then used to determine the ___ value.
a. a
b. d
c. f
d. p
37. There are two types of t-tests, the __ and the paired t-test.
a. unpaired
b. simple
c. standard
d. mean
38. In this ___t-test, your samples are related. You collect data before and after some manipulation.
a. unpaired
b. paired
c. related
d. group
39. This ___ t-test is used when you have samples that are not directly related.
a. unpaired
b. paired
c. group
d. sample
40. The Cochran variant of the t-test is used when the SD of the independent sets ___ significantly.
a. differ
b. do not differ
c. both a and b
d. neither. 1. T-tests compare __ averages.
a. 2
b. 3
c. 4
d. 5

Explanation / Answer

1. a-2

2. b-chance

3. d-0.05

4. b-0.1894

H0: 1 - 2 = 0 i.e. (1 = 2)

H1: 1 - 2 0 i.e. (1 2)

            

Assuming population variances are equal, we would have to calculate pooled-variance t-Test

Sp^2= (n1-1)S1^2+(n2-1)S2^2/(n1-1)+(n2-1)

         = (5-1)*3.8078^2+(5-1)*2.79^2/4+4

         = 11.15

tSTAT=(X1-X2)-(µ1-µ2)/Sp^2(1/n1+1/n2)

       =(13-12.6)-0/11.15(1/5+1/5)

       =0.4/2.111

       =0.1894

A B 10 9 10 9 12 14 15 16 16 17 12.6 13 Mean 2.792848009 3.807886553 SD