How do you find the area that is beyond a z-score?
did you mean something like
P(z > 2.1) ?
= 1 - P(z < 2.1)
remember that your normal distribution tables always give you the area for "less"
or you replace your tables with this applet:
http://davidmlane.com/normal.html
So using my example of P(z > 2.1)
I just click on the greater than , enter 2.1 and voila!!! , I get .0179
If you meant z-scores beyond the tables you are probably using,
look at the last entry, it should give you a prob of .99????,
e.g. for a z-score of 3.8, David Lane's applet gives you a prob of .9999
To find the area beyond a specific z-score, you can use a standard normal distribution table or a statistical calculator. The standard normal distribution table (also called the z-table) provides the area under the curve up to a certain z-score.
Here's how you can find the area beyond a given z-score using a z-table:
1. Look up the z-score in the z-table. The table provides values for different z-scores, which are typically given to two decimal places. Locate the row that corresponds to the first digit or the first two digits of your z-score and the column that corresponds to the last digit. If you can't find the exact value, round your z-score to the nearest value provided in the table.
2. Once you find the z-score in the table, observe the corresponding area value. This value represents the area under the curve up to that z-score.
3. Subtract the area you found in step 2 from 1 (since the area under the entire curve is equal to 1). This will give you the area beyond the z-score.
For example, let's say you want to find the area beyond a z-score of 1.50. Looking up this value in the z-table, you might find an area of 0.93319. Subtracting this value from 1 gives you 0.06681, which represents the area beyond the z-score of 1.50.
Alternatively, you can use statistical software or a calculator with a built-in z-score function to find the area beyond a specific z-score. These tools make the process even simpler, as they can provide the exact area beyond a given z-score without needing to consult a table.
Remember, the z-table or a calculator is crucial in obtaining accurate values for the area beyond a z-score.