Solve: 3(x- 2)= 18. X=
2 answers:
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Answer:
The margin of error of u is of 3.8.
The 99% confidence interval for the population mean u is between 27.4 minutes and 35 minutes.
Step-by-step explanation:
We have the standard deviation for the sample, which means that the t-distribution is used to solve this question.
The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So
df = 28 - 1 = 27
99% confidence interval
Now, we have to find a value of T, which is found looking at the t table, with 27 degrees of freedom(y-axis) and a confidence level of . So we have T = 2.7707
The margin of error is:
In which s is the standard deviation of the sample and n is the size of the sample.
The margin of error of u is of 3.8.
The lower end of the interval is the sample mean subtracted by M. So it is 31.2 - 3.8 = 27.4 minutes
The upper end of the interval is the sample mean added to M. So it is 31.2 + 3.8 = 35 minutes
The 99% confidence interval for the population mean u is between 27.4 minutes and 35 minutes.
Answer:
[0.9 months, 32.69 months]
Step-by-step explanation:
The mean is
The standard deviation is
Now, we have to find two values a and b such that the area under the Normal curve with mean 16.8 and standard deviation 8.1092 between a and b equals <em>95% = 0.95 </em>
Using a spreadsheet we find these values are
a = 0.906
b = 32.694
<h3>(See picture) </h3>and our 95% confidence interval for the mean number of months elapsed since the last visit to a dentist for the population of students participating in the program rounded to two decimal places is
[0.9 months, 32.69 months]
