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Noise levels at 5 airports were measured in decibels yielding the following data: 117,118,140,116,119
Question
Noise levels at 5 airports were measured in decibels yielding the following data:
117,118,140,116,119
1. Construct the 90% confidence interval for the mean noise level at such locations. Assume the population is approximately normal.
2. Calculate the sample mean for the given sample data.
3. Find the critical value that should be used in constructing the confidence interval.
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Mathematics
3 years
2021-07-21T21:39:57+00:00
2021-07-21T21:39:57+00:00 1 Answers
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Answers ( )
Answer:
1. 112.364<μ,131.636
2. mean = 122
3. critical value = +-2.1318
Step-by-step explanation:
117+118+140+116+119/5
= 610/5
= 122
the sample mean = 122
the sample standard deviation
s² = (117-122)²+(118-122)²+(140-122)²+(116-122²)+(119-122)²/5-1
= 25+16+324+36+9/4
= 410/4
= 102.5
s² = 102.5
s = √102.5
s= 10.12
SE = s/√n
= 10.12/√5
= 4.52
degree of freedom = 5-1 = 4
critical value of t = +-2.1318 using soft ware
confidence interval =
mean +- t(SE)
122-(2.1318)(4.52), 122+(2.1318)(4.52)
= [112.364, 131.636]
112.364<μ,131.636
therefore these are the answers in the ordre it was given in the question
1. 112.364<μ,131.636
2. mean = 122
3. critical value = +-2.1318