In a random sample of 28 sports cars, the average annual fuel cost was $2929 and a sample standard division $786. Construct a 90
% confidence interval for the population mean. Assume the annual fuel cost are normally distributed
1 answer:
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Answer:
(a) (6, 2)
Step-by-step explanation:
The system of equations has one of them in y= form, so it lends itself to solution by substitution.
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Using the equation for y to substitute into the first equation, we have ...
2x -y = 10
2x -(-1/2x +5) = 10 . . . . . substitute for y
2x +1/2x -5 = 10 . . . . . eliminate parentheses
5/2x = 15 . . . . . . . . . add 5, collect terms
x = 6 . . . . . . . . . . . multiply by 2/5
Using the equation for y, we have ...
y = -1/2(6) +5 = -3 +5
y = 2
The solution is (x, y) = (6, 2).
