Math worksheet with ratio and proportion word problems.

Let's solve each problem step by step:

---

Problem 1:

A dogwalker earned $79.2 in 8 hours. How much will she get for 45 hours?

#### Solution:
1. Calculate the hourly rate:
\[
\text{Hourly rate} = \frac{\text{Total earnings}}{\text{Total hours}} = \frac{79.2}{8} = 9.9 \, \text{dollars per hour}
\]

2. Calculate the earnings for 45 hours:
\[
\text{Earnings for 45 hours} = \text{Hourly rate} \times 45 = 9.9 \times 45 = 445.5
\]

#### Answer:
\[
\boxed{445.5}
\]

---

Problem 2:

For 7 kg of melted iron, a factory charges $56.10. How much will 20 bars of melted iron cost, each with a weight of 34 kg? (Round your answer to 2 dp.)

#### Solution:
1. Calculate the price per kilogram:
\[
\text{Price per kg} = \frac{\text{Total price}}{\text{Total weight}} = \frac{56.10}{7} = 8.0142857 \, \text{dollars per kg}
\]

2. Calculate the total weight of 20 bars:
\[
\text{Total weight} = 20 \times 34 = 680 \, \text{kg}
\]

3. Calculate the total cost:
\[
\text{Total cost} = \text{Price per kg} \times \text{Total weight} = 8.0142857 \times 680 \approx 5450.00
\]

#### Answer:
\[
\boxed{5450.00}
\]

---

Problem 3:

The price of 250 screws is $35. What is the price of 120 screws?

#### Solution:
1. Calculate the price per screw:
\[
\text{Price per screw} = \frac{\text{Total price}}{\text{Total screws}} = \frac{35}{250} = 0.14 \, \text{dollars per screw}
\]

2. Calculate the price for 120 screws:
\[
\text{Price for 120 screws} = \text{Price per screw} \times 120 = 0.14 \times 120 = 16.8
\]

#### Answer:
\[
\boxed{16.8}
\]

---

Problem 4:

A car drives 135 km in an hour and a half. How many minutes will it take to drive 14 km? (Remember to convert hours into minutes!)

#### Solution:
1. Convert 1 hour and a half to hours:
\[
1 \, \text{hour and a half} = 1.5 \, \text{hours}
\]

2. Calculate the speed of the car:
\[
\text{Speed} = \frac{\text{Distance}}{\text{Time}} = \frac{135}{1.5} = 90 \, \text{km/h}
\]

3. Calculate the time to travel 14 km:
\[
\text{Time} = \frac{\text{Distance}}{\text{Speed}} = \frac{14}{90} \, \text{hours}
\]

4. Convert the time from hours to minutes:
\[
\text{Time in minutes} = \left( \frac{14}{90} \right) \times 60 = \frac{14 \times 60}{90} = \frac{840}{90} = 9.3333 \, \text{minutes}
\]

#### Answer:
\[
\boxed{9.33}
\]

---

Problem 5:

4 workers make 700 parts per day. How many workers are needed to make 1540 parts a day?

#### Solution:
1. Calculate the number of parts made by one worker per day:
\[
\text{Parts per worker per day} = \frac{\text{Total parts}}{\text{Number of workers}} = \frac{700}{4} = 175 \, \text{parts per worker per day}
\]

2. Calculate the number of workers needed to make 1540 parts:
\[
\text{Number of workers} = \frac{\text{Total parts needed}}{\text{Parts per worker per day}} = \frac{1540}{175} = 8.8
\]

Since the number of workers must be a whole number, we round up to the nearest whole number:
\[
\text{Number of workers} = 9
\]

#### Answer:
\[
\boxed{9}
\]

---

Problem 6:

A pipe of 55 meters weighs 133.1 kg. What is the weight of a 23 meters pipe?

#### Solution:
1. Calculate the weight per meter:
\[
\text{Weight per meter} = \frac{\text{Total weight}}{\text{Total length}} = \frac{133.1}{55} = 2.42 \, \text{kg per meter}
\]

2. Calculate the weight of a 23-meter pipe:
\[
\text{Weight of 23 meters} = \text{Weight per meter} \times 23 = 2.42 \times 23 = 55.66
\]

#### Answer:
\[
\boxed{55.66}
\]

---

Problem 7:

5 metal boards weigh 367 kg. How much will 14 boards weigh?

#### Solution:
1. Calculate the weight per board:
\[
\text{Weight per board} = \frac{\text{Total weight}}{\text{Number of boards}} = \frac{367}{5} = 73.4 \, \text{kg per board}
\]

2. Calculate the weight of 14 boards:
\[
\text{Weight of 14 boards} = \text{Weight per board} \times 14 = 73.4 \times 14 = 1027.6
\]

#### Answer:
\[
\boxed{1027.6}
\]

---

Problem 8:

To make 45 nails, we need poles which total to 3600 mm. What is the total length of poles needed to make 28 nails?

#### Solution:
1. Calculate the length of poles needed per nail:
\[
\text{Length per nail} = \frac{\text{Total length}}{\text{Number of nails}} = \frac{3600}{45} = 80 \, \text{mm per nail}
\]

2. Calculate the total length needed for 28 nails:
\[
\text{Total length for 28 nails} = \text{Length per nail} \times 28 = 80 \times 28 = 2240 \, \text{mm}
\]

#### Answer:
\[
\boxed{2240}
\]

---

Problem 9:

A machine secures 150 nails per minute. How many hours are needed to secure 72,000 nails?

#### Solution:
1. Calculate the total time in minutes:
\[
\text{Total time (minutes)} = \frac{\text{Total nails}}{\text{Nails per minute}} = \frac{72000}{150} = 480 \, \text{minutes}
\]

2. Convert the time from minutes to hours:
\[
\text{Total time (hours)} = \frac{480}{60} = 8 \, \text{hours}
\]

#### Answer:
\[
\boxed{8}
\]

---

Problem 10:

A worker gets $486.78 for 42 hours of work. How much will she get for 54 hours?

#### Solution:
1. Calculate the hourly rate:
\[
\text{Hourly rate} = \frac{\text{Total earnings}}{\text{Total hours}} = \frac{486.78}{42} = 11.6 \, \text{dollars per hour}
\]

2. Calculate the earnings for 54 hours:
\[
\text{Earnings for 54 hours} = \text{Hourly rate} \times 54 = 11.6 \times 54 = 626.4
\]

#### Answer:
\[
\boxed{626.4}
\]

---

Problem 11:

The price for 60 pencils is $18.30. How much will we pay for 110 pencils?

#### Solution:
1. Calculate the price per pencil:
\[
\text{Price per pencil} = \frac{\text{Total price}}{\text{Total pencils}} = \frac{18.30}{60} = 0.305 \, \text{dollars per pencil}
\]

2. Calculate the price for 110 pencils:
\[
\text{Price for 110 pencils} = \text{Price per pencil} \times 110 = 0.305 \times 110 = 33.55
\]

#### Answer:
\[
\boxed{33.55}
\]

---

Final Answers:

1. \(\boxed{445.5}\)
2. \(\boxed{5450.00}\)
3. \(\boxed{16.8}\)
4. \(\boxed{9.33}\)
5. \(\boxed{9}\)
6. \(\boxed{55.66}\)
7. \(\boxed{1027.6}\)
8. \(\boxed{2240}\)
9. \(\boxed{8}\)
10. \(\boxed{626.4}\)
11. \(\boxed{33.55}\)