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Finding the Fourth Proportional to 656.87, 986.72 and 638.64

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Solution

The fourth proportional to 656.87, 986.72 and 638.64 is: 959.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    656.87 : 986.72 = 638.64 : x
  2. Step 2: Convert to fraction form
    656.87/986.72 = 638.64/x
  3. Step 3: Cross multiply
    656.87x = 986.72 × 638.64
  4. Step 4: Simplify right side
    656.87x = 630,155.67
  5. Step 5: Solve for x
    x = 630,155.67/656.87
  6. Step 6: Final answer
    x = 959.34

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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.