Answer:


The confidence interval of standard deviation is:
to 
Step-by-step explanation:
Given

See attachment for the formatted data
Solving (a): The mean
This is calculated as:

So, we have:




Solving (b): The standard deviation
This is calculated as:




--- approximated
Solving (c): 95% confidence interval of standard deviation
We have:

So:



Calculate the degree of freedom (df)



Determine the critical value at row
and columns
and 
So, we have:
---- at 
--- at 
So, the confidence interval of the standard deviation is:
to 
to 
to 
to 
Answer:
Problem B: x = 12; m<EFG = 48
Problem C: m<G = 60; m<J = 120
Step-by-step explanation:
Problem B.
Angles EFG and IFH are vertical angles, so they are congruent.
m<EFG = m<IFH
4x = 48
x = 12
m<EFG = m<IFH = 48
Problem C.
One angle is marked a right angle, so its measure is 90 deg.
The next angle counterclockwise is marked 30 deg.
Add these two measures together, and you get 120 deg.
<J is vertical with the angle whose measure is 120 deg, so m<J = 120 deg.
Angles G and J from a linear pair, so they are supplementary, and the sum of their measures is 180 deg.
m<G = 180 - 120 = 60
Answer:
Step-by-step explanation:
Givens
C = 12 * pi
C = 2*pi * r
Solution
2*pi * r = 12*pi Divide both sides by 2pi
2*pi * r/ 2*pi = 12*pi/2pi
r = 6
Answer: the diameter = 2 * r
the diameter = 12
Answer:
y = 3/2x - 5
Step-by-step explanation:
To find the equation of the line
Step 1: find slope
( 2 , -2) ( 4 , 1)
x_1 = 2
y_1 = -2
x_2 = 4
y_2 = 1
Insert the values into
m = (y_2 - y_1) / (x_2 - x_1)
m = ( 1 - (-2) / (4 - 2)
= ( 1 + 2) / ( 4 -2 )
= 3 / 2
m = 3/2
Step 2: substitute m into the equation
y = mx + c
y = 3/2x + c
Step 3: substitute any of the two points into the equation
Let's pick (4 , 1)
x = 4
y = 1
y = 3/2x + c
1 = 3/2(4) + c
1 = 3*4/2 + c
1 = 12/2 + c
1 = 6 + c
1 - 6 = c
c = 1 - 6
c = -5
Step 4 : substitute c into the equation
y = 3/2x + c
y = 3/2x - 5
The equation of the line is
y = 3/2x - 5