The estimated critical value for a sample of size 30 is 0.242. This compares favorably with the exact critical value from a statistical table, which gives D crit = 0.2417 for N = 30. You can also use the null distribution to compute a p value for an observed statistic. The p value is estimated as the proportion of statistics in the simulation From the normal percentage table we can find out the critical value. a)for 95% confidence interval the critical value is given by Za/2=Z0.05/2=Z0.025 at 5% significant value is b)for 90% confidence interval the critical value is given by Za/2=Z0.1/2 …. The formula used to compute a large-sample confidence interval for p is ± (z critical z area =0.05 1.64 2.13 Our observed value of z is 2.13 which is greater than the critical value of 1.64. We therefore reject H0. Equivalently, we can calculate the p-value for our observed mean and compare it to alpha. For this one-tailed test, the p-value is the area under the normal distribution above our observed value of z. From the z-table: The t-distribution table is a table that shows the critical values of the t distribution. To use the t-distribution table, you only need to know three values: The number of tails of the t-test (one-tailed or two-tailed) The alpha level of the t-test (common choices are 0.01, 0.05, and 0.10) Here is an example of the t-Distribution table, with z = (p-p 0) / √ p 0 (1-p 0)/n. where: p: observed sample proportion; p 0: hypothesized population proportion; n: sample size; If the p-value that corresponds to the test statistic z is less than your chosen significance level (common choices are 0.10, 0.05, and 0.01) then you can reject the null hypothesis. One Proportion Z-Test: Example ju lee. 6 years ago. when n (sample size) is greater or equal to 30, can we use use z statistics because the sampling distribution of the sample mean is approximately normal, right? if this is the case, then why does t table contain rows where the degree of freedom is 100, 1000 etc (i.e. degree of freedom = n - 1)? if n is greater or equal to .

what is z critical value