Question

#1. You are to construct a 99% confidence interval of a normally distributed population; the population standard deviation is known to be 25. A random sample of size 28 is taken; (i) the sample mean is found to 76 and (ii) the sample standard deviation was found to be 30. Construct the Confidence interval. Clearly name the standard distribution you used (z, or t or F etc.) and show work. (10 points)

Answer #1

Solution :

Here population standard deviation is known & population are
normally distributed, so we use **Z standard
distribution.**

**99% Confidence interval : ( 63.81 , 88.19 )**

**Explanation :**

Assuming that the population is normally distributed, construct
a
99 %99%
confidence interval for the population mean, based on the
following sample size of n equals 5.n=5.1, 2, 3,
44,
and
2020
In the given data, replace the value
2020
with
55
and recalculate the confidence interval. Using these results,
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99 %99%
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____ <_ u <_ _____
Q2.
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t?/2,df
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