Question 1208488
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Answer: <font color=red>0.00755</font> (approximate)


Explanation


(1-0.26)*28 = 20.72 psi or smaller would be when the warning is signaled.


Compute the z score
z = (x-mu)/sigma
z = (20.72-28)/3
z = -2.426667 approximately
z = -2.43
Then use a Z table in the back section of your textbook. 
If you don't have your textbook with you, then you can use a website like <a href="https://www.ztable.net/">this one</a>


Locate the row that starts with -2.4
Highlight the column that has 0.03 at the top.
The value 0.00755 is in this row and column. 
This value is approximate.
We can say that P(Z < -2.43) = <font color=red>0.00755</font> which is the approximate final answer in decimal form.


There's roughly a 0.755% chance that the TPMS will trigger a warning.



If you want to use technology, then you have a variety of options. <ul><li>Search online for a specialized normalCDF calculator. There are many to choose from. <a href="https://onlinestatbook.com/2/calculators/normal_dist.html">This one</a> is my favorite because it's very user friendly and draws a diagram. The only drawback is that it doesn't appear to have any option to set the rounding precision.  </li><li>Use the <a href="https://www.statisticshowto.com/ti-83-normalcdf/">NormalCDF</a> function on a TI83 or similar.</li><li>Use the <a href="https://support.google.com/docs/answer/3094021?hl=en">NormDist</a> function in a spreadsheet.</li><li>Use the <a href="https://geogebra.github.io/docs/manual/en/commands/Normal/?redirect=en">Normal</a> command in GeoGebra.</li><li>There are many other apps that you can use as well (eg: WolframAlpha, Mathematica, StatDisk, etc).</li></ul>
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