Question 302245
five measurements on the melting point of a compound: 
122.4, 121.8, 122.0. 123.0, and 122.3. 
a)The lab manual asks for a 95% confidence interval estimate for the melting point. Show her how to find this estimate.
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sample mean: 122.3
sample std: 0.4099
standard error = invT(0.975 with df=4)*0.4099/sqrt(5)= 2.7764*0.4099/sqrt(5)
= 0.5090
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95% CI: 122.3-0.4099 < u < 122.3+0.4099
95% CI: 121.79 < u < 122.71
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b) explain to your friend what a 95% confidence interval is.
I'll leave that to you.  Try it on some of your friends.
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c)would a 90% confidence interval be narrower than the 95% interval?
Higher confidence requires a broader interval.
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Cheers,
Stan H..