In order to estimate the average time spent per student on the computer terminals at a local university, data were collected for a sample of 81 business students over a one-week period. Assume the population standard deviation is 1.8 hours. With a .95 probability, the margin of error is approximately _________.

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Answer:

With a .95 probability, the margin of error is = 0.392

Step-by-step explanation:

Given -

In order to estimate the average time spent per student on the computer terminals at a local university, data were collected for a sample of 81 business students over a one-week period.

Sample size ( n ) =81

Standard deviation [tex](\sigma )[/tex] = 1.8 hours

[tex]\alpha[/tex] = 1 -.95 =.05

[tex]Z_{\frac{\alpha }{2}}[/tex] = [tex]Z_{\frac{.05 }{2}}[/tex] = 1.96           (Using Z table)

With a .95 probability, the margin of error is

Margin of error  =  [tex]Z_{\frac{\alpha }{2}}\frac{\sigma }{\sqrt{n}}[/tex]

                          = [tex]Z_{\frac{.05 }{2}} \frac{1.8 }{\sqrt{81}}[/tex]

                           = [tex]1.96\times 0.2[/tex]

Margin of error   = 0.392