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Finding the Fourth Proportional to 390.10, 585.15 and 346.90

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Solution

The fourth proportional to 390.10, 585.15 and 346.90 is: 520.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.10 : 585.15 = 346.90 : x
  2. Step 2: Convert to fraction form
    390.10/585.15 = 346.90/x
  3. Step 3: Cross multiply
    390.10x = 585.15 × 346.90
  4. Step 4: Simplify right side
    390.10x = 202,988.54
  5. Step 5: Solve for x
    x = 202,988.54/390.10
  6. Step 6: Final answer
    x = 520.35

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.