Is 21 a multiple of 6
1 answer:
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Answer:
95% confidence interval for the mean efficiency is [84.483 , 85.517].
Step-by-step explanation:
We are given that in a sample of 60 electric motors, the average efficiency (in percent) was 85 and the standard deviation was 2.
So, the pivotal quantity for 95% confidence interval for the population mean efficiency is given by;
P.Q. = ~
where, = sample average efficiency = 85
= sample standard deviation = 2
n = sample of motors = 60
= population mean efficiency
<em>So, 95% confidence interval for the mean efficiency, </em><em> is ;</em>
P(-2.0009 < < 2.0009) = 0.95
P(-2.0009 < < 2.0009 ) = 0.95
P( <
<
) = 0.95
P( <
<
) = 0.95
<u>95% confidence interval for</u> = [
,
]
= [ ,
]
= [84.483 , 85.517]
Therefore, 95% confidence interval for the population mean efficiency is [84.483 , 85.517].