Use the substitution method to solve the system of equations
1 answer:
You solve the substitution method to solve a system of equality by expressing one variable in terms of the other using one equation, and then plugging this expression in the other(s).
In this case, the first equation gives us a way to express n in terms of m. So, we can replace every occurrence of n in the second equation with the given formula.
The result is
So, the second equation turned to be an equality, i.e. an equation where both sides are the same.
This implies that the system has infinitely many solutions, because every couple such that
is a solution to the system, because it satisfies both equations: the first is trivially satisfied, whereas the second is an identity, and as such is satisfied by any value of the variable.
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Answer:
n=465 rounded up to the nearest integer
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)
represent the population standard deviation
Confidence =0.95 or 95%
Me= 0.3, represent the margion of error
n represent the sample size (variable of interest)
The margin of error is given by this formula:
(a)
And on this case we have that ME =0.3 mm and we are interested in order to find the value of n, if we solve n from equation (4) we got:
(b)
The critical value for 95% of confidence interval now can be founded using the normal distribution. And in excel we can use this formla to find it:"=-NORM.INV(0.025,0,1)", and we got , replacing into formula (b) we got:
So the answer for this case would be n=465 rounded up to the nearest integer