Q. Find the critical value zα/2 that corresponds to the given confidence level.99%zα/2=□ (Round to two decimal places as needed.).
Determine Confidence Level: To find the critical value zα/2 for a 99% confidence level, we need to determine the z-score that corresponds to the tail areas in a standard normal distribution. Since the confidence level is 99%, the area in the tails (α) is 1−0.99=0.01. This area is split equally between the two tails, so each tail has an area of 0.01/2=0.005.
Calculate Tail Areas: We need to find the z-score that has 0.005 to its right in the standard normal distribution. This is typically done using a z-table or statistical software. For a z-table, we look for the closest probability to 0.005 in the table, which will give us the corresponding z-score.
Find Z-Score: Upon looking at the z-table, we find that the z-score that corresponds to an area of 0.005 to the right is approximately 2.576. This means that zα/2 is approximately 2.576.
Round Critical Value: We are asked to round the critical value to two decimal places. The value we found is already at two decimal places, so no further rounding is necessary.
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