Let's break down and solve each part step by step:

Part 1: (a) Finding the population of Country A

The problem gives:

• 1,698 motor vehicle deaths (MVD) in Country A.
• The ratio of MVD to people is 3.13 MVD per 100,000 people.

We can set up the ratio like this: $\frac{1,698}{x} = \frac{3.13}{100,000}$

Where $x$ is the total population of Country A. Cross-multiply and solve for $x$:

$1,698 \times 100,000 = 3.13 \times x$ $x = \frac{1,698 \times 100,000}{3.13}$ $x = \frac{169,800,000}{3.13} \approx 54,249,201$

So, the population of Country A is approximately 54,249,201 people.

Part 2: (b) Finding the population of Country B

The problem gives:

• 2,110 motor vehicle deaths (MVD) in Country B.
• The ratio of MVD to people is 9.79 MVD per 100,000 people.

We set up the ratio similarly: $\frac{2,110}{x} = \frac{9.79}{100,000}$

Cross-multiply and solve for $x$:

$2,110 \times 100,000 = 9.79 \times x$ $x = \frac{2,110 \times 100,000}{9.79}$ $x = \frac{211,000,000}{9.79} \approx 21,552,605$

So, the population of Country B is approximately 21,552,605 people.

Part 3: Verifying the population of Country B

From part 2, we already calculated: $x = 21,552,605$

Thus, the population of Country B in 2021 is confirmed to be 21,552,605 people.

Part 4: (c) Finding the number of motor vehicles in Country B

We are given:

• 13.33 MVD per 100 million vehicle miles.
• 1.50 MVD per 100,000 motor vehicles.

We can use the ratio for MVD per motor vehicles: $\frac{2,110}{x} = \frac{1.50}{100,000}$

Cross-multiply and solve for $x$ (number of motor vehicles): $2,110 \times 100,000 = 1.50 \times x$ $x = \frac{211,000,000}{1.50}$ $x = 140,666,667$

The number of motor vehicles in Country B is approximately 140,666,667.

Part 5: (d) Finding the ratio of motor vehicles between Country A and Country B

We are given:

• The number of motor vehicles in Country B is approximately 15,828,957.

Let's assume the number of motor vehicles in Country A is known or calculated separately as well. We want to compute the ratio of the number of motor vehicles in Country A to Country B and scale the second quantity to 1.

For instance, if Country A had $M_A$ vehicles and Country B had $M_B$ vehicles, the ratio would be: $\text{Ratio} = \frac{M_A}{M_B}$

If we have exact numbers for both $M_A$ and $M_B$, we can calculate the ratio.

Would you like to proceed with details on calculating these, or do you have any additional clarifications needed?

Related Questions:

1. How is the population of a country determined from death rate statistics?
2. How does scaling a ratio work in real-world comparisons?
3. What are the factors that affect motor vehicle death rates between countries?
4. How can we estimate the number of motor vehicles from traffic and death rates?
5. What trends in motor vehicle deaths can be observed over time across different regions?

Tip:

When solving ratio problems, it's often helpful to set up a proportion and solve using cross-multiplication, especially when working with large numbers.