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Finding the Fourth Proportional to 390.84, 584.16 and 309.78

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Solution

The fourth proportional to 390.84, 584.16 and 309.78 is: 463.01

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.84 : 584.16 = 309.78 : x
  2. Step 2: Convert to fraction form
    390.84/584.16 = 309.78/x
  3. Step 3: Cross multiply
    390.84x = 584.16 × 309.78
  4. Step 4: Simplify right side
    390.84x = 180,961.08
  5. Step 5: Solve for x
    x = 180,961.08/390.84
  6. Step 6: Final answer
    x = 463.01

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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.