Suppose you wish to estimate a population mean correct to within 0.130.13 with a confidence level of 0.90. You do not know sigma squared σ2, but you know that the observations will range in value between 36 and 44. Complete parts a and b. Required:
a. Find the approximate sample size that will produce the desired accuracy of the estimate.
b. Calculate the approximate sample size, making the less conservative assumption that the range of the observations is equal to 6σ.

a

b

Step-by-step explanation:

From the question we are told that

    The population mean  

      The confidence level

     The range of the observation

First we obtain the z-score of which is    this is obtained from the z-table  

Generally  the standard deviation is mathematically represented as

substituting values

Now the sample size is mathematically represented as

substituting values

When the range is equal to   it implies that

=>  

=>    

So the sample size is mathematically represented as

step-by-step explanation:

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