81 random samples: were selected from a normally distributed population: and were found to have a mean of: 32.1 and a standard deviation of: 2.4. Construct a 90% confidence interval for the: population standard deviation.

2.1 < [tex]\alpha[/tex] < 2.8
1.4 < [tex]\alpha[/tex] < 1.8
28.8 < [tex]\alpha[/tex] < 37.4
4.6 < [tex]\alpha[/tex] < 7.8

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