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Finding the Fourth Proportional to 646.40, 969.36 and 261.92

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Solution

The fourth proportional to 646.40, 969.36 and 261.92 is: 392.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    646.40 : 969.36 = 261.92 : x
  2. Step 2: Convert to fraction form
    646.40/969.36 = 261.92/x
  3. Step 3: Cross multiply
    646.40x = 969.36 × 261.92
  4. Step 4: Simplify right side
    646.40x = 253,894.77
  5. Step 5: Solve for x
    x = 253,894.77/646.40
  6. Step 6: Final answer
    x = 392.78

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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.