You're nearly there. Just some more steps.
557 * x = 594 tells us
x = 594 / 557 (divide both sides by 557)
x ≈ 1.066427
When we've found this number we must realise the following:
the '1' in this answer is the 100% the car fixing costs (without taxes)
the '0.66427' stands for the tax rate.
To find the tax rate we multiply 0.66427 by 100, which gives us:
0.66427 * 100 = 6.6427 ≈ 7
So, rounded to the nearest %, the tax rate is 7%
$65.80
$26.32/8=$3.29 for a gallon
$3.29 x 20 = $65.80.
Hope this helps
Answer:
The equation of the quadratic graph is f(x)= - (1/8) (x-3)^2 + 3 (second option)
Step-by-step explanation:
Focus: F=(3,1)=(xf, yf)→xf=3, yf=1
Directrix: y=5 (horizontal line), then the axis of the parabola is vertical, and the equation has the form:
f(x)=[1 / (4p)] (x-h)^2+k
where Vertex: V=(h,k)
The directix y=5 must intercept the axis of the parabola at the point (3,5), and the vertex is the midpoint between this point and the focus:
Vertex is the midpoint between (3,5) and (3,1):
h=(3+3)/2→h=6/2→h=3
k=(5+1)/2→k=6/2→k=3
Vertex: V=(h,k)→V=(3,3)
p=yf-k→p=1-3→p=-2
Replacing the values in the equation:
f(x)= [ 1 / (4(-2)) ] (x-3)^2 + 3
f(x)=[ 1 / (-8) ] (x-3)^2 + 3
f(x)= - (1/8) (x-3)^2 + 3
Step-by-step explanation:
a. The mean can be found using the AVERAGE() function.
x = 272.7
b. The standard deviation can be found with the STDEV() function.
s = 39.9
c. The t-score can be found with the T.INV.2T() function. The confidence level is 0.04, and the degrees of freedom is 26.
t = 2.162
d. Find the lower and upper ends of the confidence interval.
Lower = 272.7 − 2.162 × 39.9 = 186.5
Upper = 272.7 + 2.162 × 39.9 = 358.9
