To find the ratio of the number of male passengers to the total number of passengers, follow these steps:

1. Number of men: 55

2. Number of women: 4

3. Total number of passengers:
   $\text{Number of men} + \text{Number of women} = 55 + 4 = 59$

4. Ratio of male passengers to total passengers:
   $\text{Ratio} = \frac{\text{Number of men}}{\text{Total number of passengers}} = \frac{55}{59}$

So, the ratio is 55/59.

Would you like more details or have any questions?

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Here are 5 related questions you might find interesting:

1. What is the ratio of female passengers to the total number of passengers?
2. What percentage of the passengers are men?
3. If 6 more women boarded the airplane, what would be the new ratio of male passengers to total passengers?
4. How many additional men would need to board for the ratio to be 60/64?
5. What is the ratio of male to female passengers?

Tip: Ratios can also be expressed as fractions, which makes them easy to convert to percentages or other forms of comparison.