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What is the z-score for a 98% confidence interval?
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Step 1:
I'll solve this step-by-step using the standard normal distribution approach:

Step 2:
: Understand the Confidence Interval

For a confidence interval, we need to find the z-score that corresponds to the given confidence level. In this case, we have a 98% confidence interval.

Step 3:
: Calculate the Area in Each Tail

A 98% confidence interval means that the total area in both tails is $$1 - 0.98 = 0.02$$.
This means each tail will have 0.02 \div 2 = 0.01 area.

Step 4:
: Find the z-score

To find the z-score, we need to look up the z-value that leaves 0.01 in each tail of the standard normal distribution.

Step 5:
: Use the Standard Normal Distribution Table

This means the critical z-values are $$-2.33$$ and $$+2.33$$.

Final Answer

Note: This value ensures that 98% of the data falls within the interval, with 1% in each tail of the distribution.