If the sample mean is less than the population mean, then the difference will be negative ...
t-statistic for mean
So, if
hope that helped
FAQs
Can t-test statistics be a negative number? | Socratic? ›
Explanation: If the sample mean is less than the population mean, then the difference will be negative ... So, if ¯x<μ , the t-statistic will be negative.
Can the t-statistic be negative? ›A negative t-statistic simply means that it lies to the left of the mean . The t-distribution, just like the standard normal, has a mean of 0 . All values to the left of the mean are negative and positive to the right of the mean.
Can test scores be negative? ›Minimum Attainable Score:
This is the lowest possible score on the test. It will usually be zero, but if a correction for guessing has been applied to the test, this score could be negative.
However, because your variables are bounded in -1 and 1 this may cause problems with one of the assumptions of the test, the normally distributed errors. You should check those. Otherwise use a non-parametric test (such as Welch). Also, a t-test works with negative values just fine.
What statistic can never be negative? ›The standard deviation can never be a negative number, due to the way it's calculated and the fact that it measures a distance (distances are never negative numbers).
Can the t-statistic be 0? ›While the null value in t tests is often 0, it could be any value. The name comes from being the value which exactly represents the null hypothesis, where no significant difference exists. Any time you know the exact number you are trying to compare your sample of data against, this could work well.
Why can't variance be negative? ›An important property of the mean is that the sum of all deviations from the mean is always equal to zero.. This is because, the negative and positive deviations cancel out each other. hence, to get positive values, the deviations are squared. This is the reason why, the variance can never be negative.
How do you interpret the t-statistic? ›The greater the magnitude of T, the greater the evidence against the null hypothesis. This means there is greater evidence that there is a significant difference. The closer T is to 0, the more likely there isn't a significant difference.
How to find p-value if t-statistic is negative? ›If your test statistic is negative, first, find the probability that Z is less than your test statistic (look up your test statistic on the Z-table and find its corresponding probability). Then double this probability to get the p-value.
When a test result is negative What does it mean? ›On your test report, you may see these terms: Negative or normal. This means "No, the test didn't find what it was looking for." So, you're unlikely to have the health problem you were tested for. But you may need more tests.
How to calculate t-statistic? ›
To calculate t-statistic:
- Determine the sample mean ( x̄ , x bar), which is the arithmetic mean of your data set.
- Find the population mean ( μ , mu).
- Compute the sample standard deviation ( s ) by taking the square root of the variance. ...
- Calculate the t-statistic as (x̄ - μ) / (s / √n) , where n denotes the sample size.
The t test estimates the true difference between two group means using the ratio of the difference in group means over the pooled standard error of both groups. You can calculate it manually using a formula, or use statistical analysis software.
What is the value of t in a one sample t-test? ›The t-value is calculated by dividing the measured difference by the scatter in the sample data. The larger the magnitude of t, the more this argues against the null hypothesis. If the calculated t-value is larger than the critical t-value, the null hypothesis is rejected.
Why can't probability be a negative number? ›For example, if you flip a fair coin many times, the probability of getting heads is the proportion of times heads occur relative to the total number of flips. Since the number of times an event occurs cannot be negative, probability is inherently non-negative.
Why can't f statistic be negative? ›The F-distribution cannot take negative values, because it represents the variance between groups and variances tend to be non-negative numbers. The F-distribution cannot take negative values, because it is a ratio of variances and variances are always non-negative numbers.
What does the t-statistic say? ›In statistics, the t-statistic is the ratio of the difference in a number's estimated value from its assumed value to its standard error. It is used in hypothesis testing via Student's t-test. The t-statistic is used in a t-test to determine whether to support or reject the null hypothesis.
What t-value is significant? ›Understanding t-Tests and Critical Values
A significance level of (for example) 0.05 indicates that in order to reject the null hypothesis, the t-value must be in the portion of the t-distribution that contains only 5% of the probability mass.