α=0.05 for a two-tailed test. Assume that the data has a normal distribution and the number of observations is greater than fifty. Find the critical z value used to test a null hypothesis.
Is the correct answer +/- 1.96?
Right.
Yes, the correct answer for a 95% confidence level (α=0.05) in a two-tailed test is approximately ±1.96.
To understand how to get this critical z value, you can follow these steps:
1. Determine the level of significance (α): In this case, α is given as 0.05.
2. Divide the level of significance by 2: Since this is a two-tailed test, you need to divide α by 2, giving you 0.05 / 2 = 0.025.
3. Look up the corresponding z value for the obtained α/2 value: In a standard normal distribution, you can find z-values using a z-table or a statistical software. For α/2 = 0.025, the corresponding z-value is approximately ±1.96.
Therefore, the critical z value for a two-tailed test with a 95% confidence level (α=0.05) is approximately ±1.96.
Yes, the correct answer is +/- 1.96. For a two-tailed test with an alpha (significance level) of 0.05, we need to divide the alpha value by 2 to split it evenly between the two tails.
Thus, each tail will have an area of 0.025. To find the critical z value, we can look up the z-score that corresponds to an area of 0.025 in the standard normal distribution table.
The critical z value for a two-tailed test at a 0.05 significance level is approximately +/- 1.96.