Answer:
2x+4
Step-by-step explanation:
Given that a is the average (arithmetic mean) of 4x and 7, b is the average of 5x and 6, and c is the average of 3x and 11
By definition of arithmetic mean,
we have
Let us calculate sum of a,b,c in terms of x
a+b+c =
Average = sum/3 =
Answer:
The confidence interval for the mean is given by the following formula:
(1)
Or equivalently:
For this case we have the interval given (3.9, 7.7) and we want to find the margin of error. Using the property of symmetry for a confidence interval we can estimate the margin of error with this formula:
Step-by-step explanation:
Previous concepts
A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".
The margin of error is the range of values below and above the sample statistic in a confidence interval.
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
represent the sample mean for the sample
population mean (variable of interest)
Solution to the problem
The confidence interval for the mean is given by the following formula:
(1)
Or equivalently:
For this case we have the interval given (3.9, 7.7) and we want to find the margin of error. Using the property of symmetry for a confidence interval we can estimate the margin of error with this formula: