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AfilCa [17]
3 years ago
13

You are interested in estimating the the mean age of the citizens living in your community. In order to do this, you plan on con

structing a confidence interval; however, you are not sure how many citizens should be included in the sample. If you want your sample estimate to be within 5 years of the actual mean with a confidence level of 94%, how many citizens should be included in your sample? Assume that the standard deviation of the ages of all the citizens in this community is 22 years.
Mathematics
1 answer:
Naddika [18.5K]3 years ago
8 0

Answer:

The sample size is    n = 68

Step-by-step explanation:

From the question we are told that

    The margin of error is  E = 5 \ years

     The standard deviation is  \sigma = 22

From the question we are told the confidence level is  94% , hence the level of significance is    

      \alpha = (100 - 94 ) \%

=>   \alpha = 0.06

Generally from the normal distribution table the critical value  of  \frac{\alpha }{2} is  

   Z_{\frac{\alpha }{2} } =  1.881

Generally the sample size is mathematically represented as  

   n = [\frac{Z_{\frac{\alpha }{2} } *  \sigma }{E} ] ^2

=>  n = [\frac{1.881 } *  22 }{5} ] ^2

=>  n = 68

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Answer:

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Step-by-step explanation:

Given A ladder leans against the side of a house

Given the angle of elevation of the ladder is 68° when the bottom of the ladder is 16 ft from the side of the house

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