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Finding the Fourth Proportional to 418.05, 624.02 and 390.69

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Solution

The fourth proportional to 418.05, 624.02 and 390.69 is: 583.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    418.05 : 624.02 = 390.69 : x
  2. Step 2: Convert to fraction form
    418.05/624.02 = 390.69/x
  3. Step 3: Cross multiply
    418.05x = 624.02 × 390.69
  4. Step 4: Simplify right side
    418.05x = 243,796.42
  5. Step 5: Solve for x
    x = 243,796.42/418.05
  6. Step 6: Final answer
    x = 583.18

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.