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Finding the Fourth Proportional to 659.76, 910.80 and 640.32

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Solution

The fourth proportional to 659.76, 910.80 and 640.32 is: 883.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    659.76 : 910.80 = 640.32 : x
  2. Step 2: Convert to fraction form
    659.76/910.80 = 640.32/x
  3. Step 3: Cross multiply
    659.76x = 910.80 × 640.32
  4. Step 4: Simplify right side
    659.76x = 583,203.46
  5. Step 5: Solve for x
    x = 583,203.46/659.76
  6. Step 6: Final answer
    x = 883.96

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.