In: Statistics and Probability
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| 20 | 4.7142857 | 22.22448980 | 
| 18 | 2.7142857 | 7.36734694 | 
| 11 | -4.2857143 | 18.36734694 | 
| 20 | 4.7142857 | 22.22448980 | 
| 16 | 0.7142857 | 0.51020408 | 
| 14 | -1.2857143 | 1.65306122 | 
| 15 | -0.2857143 | 0.08163265 | 
| 15 | -0.2857143 | 0.08163265 | 
| 14 | 1.2857143 | 1.65306122 | 
| 13 | -2.2857143 | 5.22448980 | 
| 11 | -4.2857143 | 18.36734694 | 
| 18 | 2.7142857 | 7.36734694 | 
| 20 | 4.7142857 | 22.22448980 | 
| 9 | -6.2857143 | 39.51020408 | 
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a) The standard error of the sample mean
  

Answer: 0.9575
b) We need to construct the 99% confidence interval for the population mean μ.
The critical value for α=0.01 and df = n-1 =14-1= 13, tc= t1−α/2;n−1=3.012.
The corresponding confidence interval is computed as shown below:

  
  
Answer: (12.4015, 18.1700)