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In: Statistics and Probability

. A researcher selects a random sample of 10 persons from a population of truck drivers...

. A researcher selects a random sample of 10 persons from a population of truck drivers and gives them a driver’s aptitude test. Their scores are 22,3,14,8,11,5,18,13,12, and 12.

     (a) Find the estimated standard error of the mean.

     (b) Find the 95% confidence interval for the population mean.

Solutions

Expert Solution

We have for given data,          
              
Sample mean =11.8      
Sample standard deviation =5.363  
Sample size =10     

a) Standard error of mean

=1.696


b)

Level of significance=0.05      
Degree of freedom =9      
              
t critical value is (by using t table)=2.262      
              
Confidence interval formula is               


=(7.96,15.64)          
              
              
Lower confidence limit=7.96  
              
Upper confidence limit= 15.64  

orchestra answered 1 year ago
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