How do I use t-distribution to estimate the tα/2

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In summary, the conversation discusses using the t-distribution to estimate the tα/2 and verifying the result using the empirical rule. The concept of α as the level of probability for testing is also explained. The conversation then moves on to discussing a problem that involves finding the population mean and standard deviation, listing possible samples of size 3, and using the t-distribution to estimate the tα/2 for small sample sizes. The conversation ends with a reminder to post homework questions in the appropriate forum.
  • #1
lilyungn
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Hi, I need help understanding how do I use t-distribution to estimate the tα/2 . Also what is meant when it asks "verify your result with empirical rule"
 
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  • #2
Do you understand what α is?
 
  • #3
no i dont, what is it?
 
  • #4
It is the level of probability to be used for testing. The probability that the result is due to chance.

Do you know what a probability distribution is?
 
  • #5
Basically I'm working on a problem that asks that part of the question. I have solved for the population mean, and have different samples with 3 data in them. I calculated the x-bar of those samples with the standard dev and have gotten their confidence intervals.
 
  • #6
That's all very good; how does your original question about the t distribution relate to the rest?
 
  • #7
here is the question:

- Find the population mean and its standard deviation
- List all possible samples of size 3 from those 5 units
- From each sample, compute the mean, standard deviation, and 95% confidence interval. Use t-distribution to estimate the tα/2 because we have a small size.
 
  • #8
Questions like this belong in the Homework forum. Please post there next time. Hey, I don't make the rules around here.
 

Related to How do I use t-distribution to estimate the tα/2

1. What is a t-distribution?

The t-distribution is a statistical probability distribution that is used to estimate the population mean when the sample size is small and the population standard deviation is unknown. It is similar to the normal distribution, but takes into account the added uncertainty due to the smaller sample size.

2. How do I calculate the tα/2 value?

The tα/2 value is the critical value associated with a specific confidence level and degrees of freedom. It can be found using a t-table or by using a statistical software. The formula for calculating it is tα/2 = t(1-α/2, df), where α is the level of significance and df is the degrees of freedom.

3. How do I find the degrees of freedom for a t-distribution?

The degrees of freedom for a t-distribution is equal to the sample size minus one. For example, if you have a sample size of 20, then the degrees of freedom would be 19.

4. What is the purpose of using t-distribution to estimate tα/2?

The t-distribution is used to estimate tα/2 in order to calculate confidence intervals and perform hypothesis testing. It takes into account the added uncertainty due to the small sample size, resulting in more accurate estimates of the population mean.

5. How do I interpret the tα/2 value?

The tα/2 value represents the critical value at which a certain percentage of the t-distribution falls below it. For example, if you have a tα/2 value of 2.042 and a confidence level of 95%, then you can say that 95% of the t-distribution falls below 2.042. This value is used to determine the margin of error in confidence intervals and to make decisions in hypothesis testing.

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