These are the means and standard deviations for samples of building heights
in two different cities.
City A
Mean: 120 ft
Standard deviation: 20 ft
City B
Mean: 240 ft
Standard deviation: 12 ft
Select the two true statements.
D
A. City A's heights are more spread out than city B's heights.
B. City A's heights are less spread out than city B's heights.
c. City A has a lower average height than city B.
D. City A has a greater average height than city B.

A & C

A- City A’s heights are more spread out than city B’s heights.

C- City A has a lower average height than city B.

Length = 13 in

Width = 10 in

Step-by-step explanation:

Let L be the length.

Let W be te width.

From the question given above, the Lenght is 3 more that the width i.e

L = 3 + W

Next, we shall determine the width (W). This can be obtained as follow:

Length (L) = 3 + W

Width (W) = W

Area (A) = 130 in²

A = L × W

130 = (3 + W) × W

Clear bracket

130 = 3W + W²

Rearrange

W² + 3W – 130 = 0

Solving by formula method

W = –b ± √(b² – 4ac) / 2a

a = 1

b = 3

c = –130

W = –3 ± √(3² – 4 × 1 × –130) / 2 × 1

W = –3 ± √(9 + 520) / 2

W = –3 ± √(529) / 2

W = –3 ± 23 / 2

W = –3 + 23 / 2 or –3 – 23 / 2

W = 20/2 or –26/2

W = 10 or –13

Since measurement can not be negative, the width is 10 in.

Finally, we shall determine the length. This can be obtained as follow:

L = 3 + W

W = 10

L = 3 + 10

L = 13 in

SUMMARY

Length = 13 in

Width = 10 in