Contemporary Mathematics

# Chapter 13

13.1
1.
46 in
13.2
1.
34 scales
13.3
1.
1.618
13.4
1.
1.25, which is close to a golden rectangle
13.5
1.
210 gal
13.6
1.
1,050,000 gal
13.7
1.
9,828 million gal of water
13.8
1.
15.8 kW
13.9
1.
$14.18 13.10 1.$0.06
13.11
1.
288 kW
13.12
1.
1.8 mg in 200 mL
13.13
1.
6 pills
13.14
1.
42 mg
13.15
1.
13 mL
13.16
1.
Yara, Jeffrey
2.
5
13.17
1.
birds chirping
2.
window air conditioner
3.
garbage disposal
4.
live outdoor concert
13.18
1.
up G, down F
2.
up C, down B
3.
up G, down F
13.19
1.
up E, down B
2.
up D#, down B
3.
up F#, down D
13.20
1.
G, G#, A, A#, B, C, C#, D, D#, E, F, F#
13.21
1.
83 Hz
13.22
1.
10 games
2.
66 games
3.
300 games
13.23
1.
4 games
2.
11 games
3.
24 games

1.
1.618
2.
1, 1, 2, 3, 5, 8, 13, 21, 34, 55
3.
A rectangle whose length divided by the width is approximately equal to $\mathit{ϕ}$ or 1.618.
4.
$1\,{\rm{kW}} = 1{,}000\,{\rm{watts}}$
5.
100 gal
6.
33 1/3 hours
7.
17 hours
8.
medicine dosage required, weight of drug by volume
9.
b Research on coronavirus vaccines began approximately 10 years before the COVID-19 pandemic hit the world.
10.
Mathematical modeling is a graphical representation of a behavior, such as exposure to a virus. It can be helpful in mapping contract tracing with virus exposure during a pandemic.
11.
Frequency is a static measured value, whereas pitch is subjective.
12.
higher
13.
20–20,000 Hz
14.
increase
15.
0 dB
16.
20–17,000Hz
17.
It doubles.
18.
Data analytics is used in sports to analyze data on team’s players, potential recruits, opposing teams, and opposing players. This helps to find patterns and make predictions for future results.
19.
Soccer (football)
20.
$n\left( {n - 1} \right)/2$
21.
$n - 1$