What is subtraction?
2 answers:
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Answer:
Step-by-step explanation:
Hello!
You have sample of n=7 with mean X[bar]= 1403 and standard deviation S=27 and are required to estimate the mean with a 95%CI.
Asuming this sample comes from a normal population I'll use a stuent t to estimate the interval (a sample of 7 units is too small for the standard normal to be accurate for the estimation):
[X[bar]± *
]
[1403±2.365*]
[1378.87;1427.13]
The margin of error is the semiamplitude of the interval and you can calculate it as:
With a confidence level of 95% you'd expect that the real value of the mean is contained by the interval [1378.87;1427.13], the best estimate of the mean value is expected to be ± 24.13 of 1403.
I hope it helps!
Answer:
Step-by-step explanation:
The confidence interval to estimate the population mean is given by :_
Given : Sample size : n= 60 , the sample is a large sample (n>30), so we can apply z-test.
Sample mean =
Standard deviation :
Level of confidence:
Then, critical z-value =
Then, a 95% confidence interval estimate of the population mean will be
Hence, the 95% confidence interval to estimate the population mean = .