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Finding the Fourth Proportional to 651.47, 978.11 and 431.45

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Solution

The fourth proportional to 651.47, 978.11 and 431.45 is: 647.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    651.47 : 978.11 = 431.45 : x
  2. Step 2: Convert to fraction form
    651.47/978.11 = 431.45/x
  3. Step 3: Cross multiply
    651.47x = 978.11 × 431.45
  4. Step 4: Simplify right side
    651.47x = 421,998.51
  5. Step 5: Solve for x
    x = 421,998.51/651.47
  6. Step 6: Final answer
    x = 647.77

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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.