Answer:
The margin of error is [tex]E = 1.96 * \frac{ 0.92}{\sqrt{28 } }[/tex]
Step-by-step explanation:
From the question we are told that
The sample size is [tex]n = 28[/tex]
The sample mean is [tex]\= x = 2.4 \ hr[/tex]
The standard deviation is [tex]\sigma = 0.92 \ hr[/tex]
Given that the confidence level is 95% the the level of significance can be evaluated as
[tex]\alpha = 100 -95[/tex]
[tex]\alpha = 5 \%[/tex]
[tex]\alpha = 0.05[/tex]
Next we obtain the critical value of [tex]\frac{\alpha }{2}[/tex] from the normal distribution table,the value is [tex]Z_{\frac{\alpha }{2} } = Z_{\frac{0.05}{2} } = 1.96[/tex]
Generally the margin of error is mathematically represented as
[tex]E = Z_{\frac{\alpha }{2} } * \frac{\sigma }{\sqrt{n} }[/tex]
substituting values
[tex]E = 1.96 * \frac{ 0.92}{\sqrt{28 } }[/tex]
[tex]E = 0.3408[/tex]