Question

In: Statistics and Probability

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.

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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