it took 85 wsu students an average of 36 minutes to commute to campus( with a...

it took 85 wsu students an average of 36 minutes to commute to campus( with a standard deviation of 3.5 minute ). at the 95% confidence level, construct a confidence interval within which lies the mean commute time of all WSU students.

Solutions

Expert Solution

= Solution :

Given that,

Point estimate = sample mean = = 36

Population standard deviation = = 3.5

Sample size n =85

At 95% confidence level the z is ,

= 1 - 95% = 1 - 0.95 = 0.05

/ 2 = 0.05 / 2 = 0.025

Z/2 = Z0.025 = 1.96 ( Using z table )

Margin of error = E = Z/2 * ( / $\sqrt$ n)

= 1.96 * (3.5 / $\sqrt$ 85 )

= 0.744
At 95% confidence interval
is,

- E < < + E

36- 0.744 < < 36+ 0.744

(35.256 ,36.744)

LOWER BOUND 35.256

UPPER BOUND 36.744

orchestra answered 1 year ago

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