Question: Which condition must be met to conduct a test for the difference in two sample means using a z-statistic?
The data must be at least of nominal scale.
What conditions must be met for the t test to be applied?
The test relies on a set of assumptions for it to be interpreted properly and with validity. Among these assumptions, the data
must be randomly sampled from the population of interest
and the data variables must follow a normal distribution.
Which of the conditions must be met to perform the two sample t-test?
Question: Which condition must be met to perform the two-sample t test? There can be no skewness in either of the distributions.
The two random samples must be selected from two distinct populations. The two random samples must be selected from the same population
.
Which of the following conditions must be met to conduct a two proportion significance test?
The test procedure, called the two-proportion z-test, is appropriate when the following conditions are met:
The sampling method for each population is simple random sampling
. The samples are independent. Each sample includes at least 10 successes and 10 failures.
What conditions must be met in order to use the two sample z interval for a difference between two proportions?
What conditions must be met in order to use the Two-sample z Interval for a difference between Two Proportions?
RANDOM
: the data are produced by a random sample of size n1 from population 1 and a random sample of size n2 from population 2 or by two groups of size n1 and n2 in a randomized experiment.
In which condition do we apply t-test and ANOVA?
The Student's t test is
used to compare the means between two groups
, whereas ANOVA is used to compare the means among three or more groups. In ANOVA, first gets a common P value. A significant P value of the ANOVA test indicates for at least one pair, between which the mean difference was statistically significant.
When should you use the t-test?
When to use a t-test
A t-test can only be used
when comparing the means of two groups (a.k.a. pairwise comparison)
. If you want to compare more than two groups, or if you want to do multiple pairwise comparisons, use an ANOVA test or a post-hoc test.
Are the conditions for performing a two sample t test satisfied?
Conditions for conducting two sample t-test for means: …
The two samples are random and independent of each other
. 3.) Population variances are equal and unknown.
What is a two sample t-test used for?
The two-sample t-test (also known as the independent samples t-test) is a method used to
test whether the unknown population means of two groups are equal or not
.
What does Z * represent?
It means the
“critical value of z
.” This is taken from wikipedia: In statistics, z* and t* are given critical points for z-distributions and t-distributions, respectively.
How do you compare proportions between two groups?
- Calculate the sample proportions. for each sample. …
- Find the difference between the two sample proportions,
- Calculate the overall sample proportion. …
- Calculate the standard error:
- Divide your result from Step 2 by your result from Step 4.
Why are two sample z procedures hardly ever used?
In practice, the two‐sample z‐test is not used often, because
the two population standard deviations σ
1
and σ
2
are usually unknown
. Instead, sample standard deviations and the t‐distribution are used.
What is the z value that is used for a 95% confidence interval?
The Z value for 95% confidence is
Z=1.96
.
How are z and t confidence intervals different?
What's the key difference between the t- and z-distributions? The standard normal or z-distribution assumes that you know the population standard deviation. The t-distribution is based on the sample standard deviation.
What is the ANOVA test used for?
Like the t-test, ANOVA helps you
find out whether the differences between groups of data are statistically significant
. It works by analyzing the levels of variance within the groups through samples taken from each of them.
What is the difference between t-test and chi square?
A t-test tests a null hypothesis about two means; most often, it tests the hypothesis that two means are equal, or that the difference between them is
zero
. … A chi-square test tests a null hypothesis about the relationship between two variables.
