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Finding the Fourth Proportional to 651.74, 978.16 and 431.72

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Solution

The fourth proportional to 651.74, 978.16 and 431.72 is: 647.94

Step by Step Solution

  1. Step 1: Write the proportion equation
    651.74 : 978.16 = 431.72 : x
  2. Step 2: Convert to fraction form
    651.74/978.16 = 431.72/x
  3. Step 3: Cross multiply
    651.74x = 978.16 × 431.72
  4. Step 4: Simplify right side
    651.74x = 422,291.24
  5. Step 5: Solve for x
    x = 422,291.24/651.74
  6. Step 6: Final answer
    x = 647.94

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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.