2020年12月6日 · Percentage points. It has been traditional to use $z_{0.025}$ as the value $1.96$ that cuts probability $0.025$ from the upper tail of a standard normal distribution.

2020年12月27日 · I want to know for sure when we compute the 95% confidence interval for mean/prop, we get z = qnorm(0.95) or z = qnorm(0.975)?

2017年9月7日 · Where z = 1.96. These areas are equal to 0.025 because they represent the leftover areas under the standard normal distribution below -1.96 and above 1.96, which adds up to 5% or 0.05. I want to know how I can mathematically show that z = 1.96.

2023年2月19日 · I was watching a Youtube video about Confidence Intervals and came across a slide that threw me:. I get that the blue region is $1-\alpha$ (often 0.95 in practice) while the bits to the edge are each $\frac{\alpha}{2}$ (often 0.025 in practice).

2015年7月14日 · Most normal tables are constructed to give you $\mathbb{P}(Z \leq z)$ or $\mathbb{P}(0 < Z \leq z)$. So the precise way to look up the table will depend on which type of table you're using, but in most cases you will need to look up the value of $1 - \alpha$ or $1 - \alpha/2$ (again depending on the table and on the test you're doing).

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2021年2月11日 · With a z-score you can look-up the p-value (percentage) in a table. For t-scores you just get a table to look up the t-score for your desired alpha level given the degrees of freedom you have. You can compare that score with your t-score but what if …

2021年11月26日 · Stack Exchange Network. Stack Exchange network consists of 183 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

If quantile and a z-score are the same thing, then I thought that it should be 0.475 => 1.96 (and not 0.975 => 2)? (Since the confidence interval is 95% the alpha value is going to be 0.05 and the tails will have an area of 0.025 each. Having this the critical z-value is going to be 1.96 (z of 0.475 (0.5 - 0.025)), right?)

2018年1月23日 · Stack Exchange Network. Stack Exchange network consists of 183 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.