Chapter 10
SS = a. (df)(s^2) b. (df)(s) c. (n)(s^2) d. (n)(s)
(df)(s^2)
Calculate pooled variance: n1 = 11 n2 = 21 df1 = 10 df2 = 20 s1 = 5.4 SS1 = 291.6 SS2 = 12482
51.327
Calculate s2: n1 = 11 n2 = 21 df1 = 10 df2 = 20 s1 = 5.4 SS1 = 291.6 SS2 = 12482
7.9
Which of the following null hypotheses is appropriate for an independent-measures t-test? a. H0: u not = 6 b. H0: u1 not = u2 c. H0: u1 = u2 d. H0: u = 0
H0: u1 = u2
t test for two independent samples - two-tailed example: True or False When finding the critical t-scores that forms the boundaries of the critical region for α = 0.05 you divide the α 0.05 by 2 and use 0.0250 to find the t-scores
True
s1 = a. √SS1/df1) b. √SS1/n1)
√SS1/df1)
s2 = a. √SS2/df2) b. √SS2/n2)
√SS2/df2)
pooled variance = a. SS1 + SS2 / df1 + df2 b. SS1 + SS2 / n1 + n2
SS1 + SS2 / df1 + df2
Calculate SS1: n1 = 11 n2 = 21 df1 = 10 df2 = 20 s1 = 5.4 SS2 = 12482
SS1 = 291.6
True or False In order to calculate the standard error, you first need to calculate the pooled variance.
True
True or False In order to calculate the t statistic, you first need to calculate the standard error under the assumption that the null hypothesis is true.
True
Which of the following experiments uses independent samples? a. you want to compare the mean first-month weight gain of premature babies to that of full-term babies. So you can compare the mean first-month weight gain of a random sample of premature babies to the mean first-month weight gain of a random sample of full-term babies. b. You want to compare the mean Hamilton depression sample of teenage girls who attend a weeklong self-image camp to the known mean Hamilton score for teenage girls.
a
For the independent-measures t test, which of the following describes the pooled variance? a. the difference between the standard deviation of the two samples b. the variance across all the data values when both samples are pooled together c. a weighted average of the two sample variances (weighted by the sample sizes) d. an estimate of the standard distance between the differnece in sample means (M1 - M2) and the differnece in the corresponding population means (u1 - u2)
a weighted average of the two sample variances (weighted by the sample sizes)
For the independent-measures t test, which of the following describes the estimated standard error M1 - M2? a. the difference between the standard deviation of the two samples b. the variance across all the data values when both samples are pooled together c. a weighted average of the two sample variances (weighted by the sample sizes) d. an estimate of the standard distance between the differnece in sample means (M1 - M2) and the differnece in the corresponding population means (u1 - u2)
an estimate of the standard distance between the differnece in sample means (M1 - M2) and the differnece in the corresponding population means (u1 - u2)
In calculating the _____________(estimated standard error M1 - M2, pooled variance), you typically first need to calculate the ____________(estimated standard error M1 - M2, pooled variance). The ________________(estimated standard error M1 - M2, pooled variance) is the value used in the denominator of the t statistic for the independent-measures t tests.
estimated standard error M1 - M2 pooled variance (estimated standard error M1 - M2
Critical t-scores = +/- 1.995 t statistic = 2.55 The t statistic ________(lies, does not lie) in the critical region. Therefore, the null hypothesis is ____________(rejected, not rejected). You ________(can, can not) conclude. Thus, it can be said that the two means are ___________(significantly, not significantly) different from one another.
lies rejected can significant
In order to calculate the standard error, you first need to calculate the ________________(pooled variance., standard error)
pooled variance
In order to calculate the t statistic, you first need to calculate the__________ (standard error, pooled variance) under the assumption that the null hypothesis is true.
standard error
r^2 = a. t^2/t^2+df b. t^2/t^2+n c. t/t+df
t^2/t^2+df
