To find the critical value Z0.01, we need to determine the z-score that corresponds to the cumulative probability of 0.01 in the standard normal distribution. The critical value is used in hypothesis testing and confidence intervals to define the threshold for rejecting the null hypothesis.
In a standard normal distribution, we look for the value of Z such that the area to the left of Z is equal to 0.01. This means we are interested in the lower tail of the distribution.
Using a standard normal distribution table or a calculator, we find that the critical value Z0.01 is approximately -2.33. This implies that if our test statistic is less than -2.33, we would reject the null hypothesis at the 1% significance level.