"solve the following system of linear equations using substitution." y=-6x and 4x+5y=52
1 answer:
You substitute y with -6 and get the equation 4x+5(-6)=52 from there you solve.
First you do 5 times -6 and get -30 and drop everything else to get 4x+(-30)=52
Second you take the -30 and add 30 to each side to leave you with 4x=82
Third you divide both sides by 4 and that leaves you with x=20.5
So your answer is 20.5 or 20
First you do 5 times -6 and get -30 and drop everything else to get 4x+(-30)=52
Second you take the -30 and add 30 to each side to leave you with 4x=82
Third you divide both sides by 4 and that leaves you with x=20.5
So your answer is 20.5 or 20
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Answer:
So on this case the 95% confidence interval would be given by (38.608;39.392)
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
n=25 represent the sample size
Solution to the problem
The confidence interval for the mean is given by the following formula:
(1)
The margin of error is given by:
Since the Confidence is 0.95 or 95%, the value of and
, and we can use excel, a calculator or a tabel to find the critical value. The excel command would be: "=-NORM.INV(0.025,0,1)".And we see that
And replacing we got:
Now we have everything in order to replace into formula (1):
So on this case the 95% confidence interval would be given by (38.608;39.392)