(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

The data i'm working with is

Sample mean(voltage)=128.25

variance=9/20

sample size=20

SD=3

Z=-2.61

3. The attempt at a solution

The first part of what I was doing was a hypothesis test that the true voltage is 130 compared to the alternative less than 130. Which I worked out the Z= -2.61

What I have to do now is calculate the critical value for this test using a 1% significance level.. I know the answer because I looked it up in the text book its 128.44 but for the life of me I can't work out any formulas that will help me... can anyone shed some light??? Thanks :)

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# Homework Help: How do you find a critical value when using a 1% significance level

Can you offer guidance or do you also need help?

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