t-test (independent sample)

The comparison distribution for a test of independent sample indicates _____________.

• distribution of proportional variance scores

• Z distribution (that is, a normal curve)

• distribution of differences between means

• distribution of differences between variances

When conducting a t test for independent means, a typical research hypothesis might be _________.

• the mean of Sample 1 is the same as the mean of Sample 2

• the mean of Population 1 is the same as the mean of Population 2

• the mean of Sample 1 is greater than the mean of Sample 2

• the mean of population 1 is greater than the mean of population 2

The degrees of freedom used for a t-test of independent means is ___________.

• the degrees of freedom for sample 1, divided by the sum of the degrees of freedom for both samples

• the average of the degrees of freedom for the two samples

• the sum of the two sample sizes, minus one

• the sum of the degrees of freedom of the two independent samples

One of the assumptions for the t-test of independent means is that ___________.

• sample means are not significantly different

• the mean of the distribution of differences between means is 1

• the variance of each of the population is the same

• the mean of each of the population vary by not more than 1 standard deviation

Which of the following assumptions does not apply to the t-test of independent means?

• normality

• homogeneity of variance

• independence of scores

• unweighted averages

A t-test for independent means is reported as "t (28) = 4.21, p < .01." This means _________.

• the result is not statistically significant

• there were 28 participants in the study

• the t-score was significant

• the effect size is strong

When conducting a t test for independent means, a typical null hypothesis is that the mean of Population 1 equals the mean of (a)   .

To conduct a t test for independent means, the populations should both be normally distributed and have the same (a)   .

A study with two groups of 10 participants each and a t-value of 2.21 was significant at the .05 significance level would be written as (a)   .

In which of the following situations would a t test for independent means be conducted?

• A comparison of participants' logical reasoning skills with the general population

• A comparison of participants' scores on a skills test before and after attending a training session intended to improve the skill

• A comparison of scores of participants in a memory study where one group is assigned to learn the words in alphabetical order and another group is assigned to learn the words in order of length of the word

• A comparison of SPM scores of a group of 10 students in 2020 versus general population in 2019