Answer:
b. It will decrease by a factor of 2
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of
, and a confidence interval
, we have the following confidence interval of proportions.

In which
z is the zscore that has a pvalue of
.
The lower end of the interval is given by:

The upper end of the interval is given by:

The length of the interval is the subtraction of the upper end by the lower end, so it is:

This means that the length is inverse proportional to the square root of the size of the sample.
So, if the sample size is multiplied by 4, the length of the interval is going to decrease by a factor of 2.
Answer:
The option is C i.e 115°, 65°. proof is given below.
Step-by-step explanation:
Given:
ABCD is a quadrilateral.
m∠ A = 100 + 5x
m∠ B = 77 - 4y
m∠ C = 106 + 3x
m∠ D = 47 + 6y
To Prove:
ABCD is a parallelogram if opposing angles are congruent by finding the measures of angles.
m∠ A = m∠ C and
m∠ B = m∠ D
Proof:
ABCD is a quadrilateral and is a parallelogram if opposing angles are congruent.
∴ m∠ A = m∠ C
On substituting the given values we get
∴ 100 + 5x = 106 +3x
∴ 
m∠ A = 100 + 5x = 100 + 5 × 3 =100 + 15 = 115°
m∠ C = 106 + 3x = 106 + 3 ×3 =106 + 9 = 115°
∴ m∠ A = m∠ C = 115°
Similarly,
∴ m∠ B = m∠ D
77 - 4y = 47 + 6y
10y = 77 - 47
10y =30
∴
m∠ B = 77 - 4y =77 - 4 × 3 = 77 - 12 = 65°
m∠ D = 47 + 6y = 47 + 6 × 3 = 47 + 18 = 65°
∴ m∠ B = m∠ D = 65°
Therefore the option is C i.e 115°, 65°
I think you can draw two of them.
As you walk around the triangle in the clockwise direction,
you can run into the sides in the order of
3 ==> 4 ==> 1
or in the order of
3 ==> 1 ==> 4 .
Those are mirror images of each other. So they're not congruent,
and I think they're considered different triangles.
Let us say that:
x = cost of shorts
y = cost of slacks
z = cost of sports coat
From the given statements, we can create the following
equations:
eqtn 1: 3 x + y =
10.96
eqtn 2: 7 x + 2 y +
z = 30.40
eqtn 3: 4 x + z =
14.45
Rewrite eqtn 1 explicit to y:
y = 10.96 – 3 x -->
eqtn 4
Rewrite eqtn 3 explicit to z:
z = 14.45 – 4x -->
eqtn 5
Plug in the values of y (eqtn 4) and z (eqtn 5) to eqtn
2:
7 x + 2 (10.96 – 3 x) + 14.45 – 4 x = 30.40
7 x + 21.92 – 6 x + 14.45 – 4 x = 30.40
- 3 x + 36.37 = 30.40
- 3 x = - 5.97
x = 1.99
Eqtn 4:
y = 10.96 – 3 x
y = 10.96 – 3 (1.99)
y = 4.99
Eqtn 5:
z = 14.45 – 4x
z = 14.45 – 4 (1.99)
z = 6.49
Therefore each shirt cost $1.99, each slacks cost $4.99,
and each sports coat cost $6.49.
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