Answer and Step-by-step explanation:
we have the following data:
Point estimate = sample mean = \ bar x = 12.39
Population standard deviation = \ sigma = 3.7
Sample size = n = 177
a) the margin of error with a 90% confidence interval
α = 1 - 90%
alpha = 1 - 0.90 = 0.10
alpha / 2 = 0.05
Z \ alpha / 2 = Z0.05 = 1,645
Margin of error = E = Z \ alpha / 2 * (\ sigma / \ sqrtn)
we replace:
E = 1.645 * (3.7 / \ sqrt177)
Outcome:
E = 0.46
b) margin of error with a 99% confidence interval
α = 1-99%
alpha = 1 - 0.99 = 0.01
alpha / 2 = 0.005
Z \ alpha / 2 = Z0.005 = 2,576
Margin of error = E = Z \ alpha / 2 * (\ sigma / \ sqrtn)
we replace:
E = 2,576 * (3.7 / \ sqrt177)
Outcome:
E = 0.72
c) A larger confidence interval value will increase the margin of error.
Answer:
A
Step-by-step explanation:
A secant is a line that goes through a circle at two points.
(

)we need 3 equations
1. midpoint equation which is (

) when you have 2 points
2. distance formula which is D=

3. area of trapezoid formula whhic is (b1+b2) times 1/2 times height
so
x is midpoint of B and C
B=11,10
c=19,6
x1=11
y1=10
x2=19
y2=6
midpoint=(

)
midpoint=(

)
midpoint= (15,8)
point x=(15,8)
y is midpoint of A and D
A=5,8
D=21,0
x1=5
y1=8
x2=21
y2=0
midpoint=(

)
midpoint=(

)
midpoint=(13,4)
Y=(13,4)
legnths of BC and XY
B=(11,10)
C=(19,6)
x1=11
y1=10
x2=19
y2=6
D=

D=

D=

D=

D=

BC=

X=15,8
Y=(13,4)
x1=15
y1=8
x2=13
y2=4
D=

D=

D=

D=

D=

XY=

the thingummy is a trapezoid
we need to find AD and BC and XY
we already know that BC=

and XY=

AD distance
A=5,8
D=21,0
x1=5
y1=8
x2=21
y2=0
D=

D=

D=

D=

D=

AD=

so we have
AD=

BC=
XY=

AD and BC are base1 and base 2
XY=height
so
(b1+b2) times 1/2 times height
(

) times 1/2 times

=
(

) times \sqrt{5} [/tex] =

=

=80

=252.982
X=(15,8)
Y=(13,4)
BC=

XY=

Area=80

square unit or 252.982 square units
Well if there is 28 feet, that would be (12x28) 336 inches, and 16 inches between the plug and the first light, there would be only 320 inches left for lights. therefore, if there are 4 inches between each light, we divide 320 by 4. the answer we get is 80. there are 80 lights.