Answer:
We use students' t distribution therefore degrees of freedom is v= n-2
Step-by-step explanation:
<u>Confidence Interval Estimate of Population Regression Co efficient β.</u>
To construct the confidence interval for β, the population regression co efficient , we use b, the sample estimate of β. The sampling distribution of b is normally distributed with mean β and a standard deviation σ.y.x / √(x-x`)². That is the variable z = b - β/σ.y.x / √(x-x`)² is a standard normal variable. But σ.y.x is not known so we use S.y.x and also student's t distribution rather than normal distribution.
t= b - β/S.y.x / √(x-x`)² = b - β/Sb [Sb = S.y.x / √(x-x`)²]
with v= n-2 degrees of freedom.
Consequently
P [ - t α/2< b - β/Sb < t α/2] = 1- α
or
P [ b- t α/2 Sb< β < b+ t α/2 Sb] = 1- α
Hence a 100( 1-α) percent confidence for β the population regression coefficient for a particular sample size n <30 is given by
b± t α/2 Sb
Using the same statistic a confidence interval for α can be constructed in the same way for β replacing a with b and Sa with Sb.
a± t α/2 Sa
Using the t statistic we may construct the confidence interval for U.y.x for the given value X0 in the same manner
Y~0 ± t α/2(n-2) SY~
Y~0= a+b X0
The total price for the meal is $79.69
20% of $63 is $12.6
And 6.5% of $63 is $4.09
$4.09+$12.6+$63=$79.69
√144 = √12^2 = 12
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Answer:
130º
Step-by-step explanation:
a line is 180º so if one angle is 50 then it's just 180-50
Answer:
(x, y) = (4, 1)
Step-by-step explanation:
The coefficients of x are the same, so we can cancel the x-terms by subtracting one equation from the other. We want to do this so the resulting y-coefficient will be positive. That means we want to subtract the second equation from the first:
(-2x +y) -(-2x -4y) = (-7) -(-12)
5y = 5 . . . . . . . . simplify
y = 1 . . . . . . . . divide by 5
-2x +1 = -7 . . . . . substitute for y in the first equation
-2x = -8 . . . . . subtract 1
x = 4 . . . . . . divide by -2
The solution is (x, y) = (4, 1).
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A graphing calculator easily verifies the solution.
