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Finding the Fourth Proportional to 390.10, 585.60 and 207.40

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Solution

The fourth proportional to 390.10, 585.60 and 207.40 is: 311.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.10 : 585.60 = 207.40 : x
  2. Step 2: Convert to fraction form
    390.10/585.60 = 207.40/x
  3. Step 3: Cross multiply
    390.10x = 585.60 × 207.40
  4. Step 4: Simplify right side
    390.10x = 121,453.44
  5. Step 5: Solve for x
    x = 121,453.44/390.10
  6. Step 6: Final answer
    x = 311.34

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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.