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Finding the Fourth Proportional to 660.32, 989.64 and 312.90

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Solution

The fourth proportional to 660.32, 989.64 and 312.90 is: 468.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.32 : 989.64 = 312.90 : x
  2. Step 2: Convert to fraction form
    660.32/989.64 = 312.90/x
  3. Step 3: Cross multiply
    660.32x = 989.64 × 312.90
  4. Step 4: Simplify right side
    660.32x = 309,658.36
  5. Step 5: Solve for x
    x = 309,658.36/660.32
  6. Step 6: Final answer
    x = 468.95

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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.