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Finding the Fourth Proportional to 656.90, 905.48 and 643.94

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Solution

The fourth proportional to 656.90, 905.48 and 643.94 is: 887.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    656.90 : 905.48 = 643.94 : x
  2. Step 2: Convert to fraction form
    656.90/905.48 = 643.94/x
  3. Step 3: Cross multiply
    656.90x = 905.48 × 643.94
  4. Step 4: Simplify right side
    656.90x = 583,076.25
  5. Step 5: Solve for x
    x = 583,076.25/656.90
  6. Step 6: Final answer
    x = 887.61

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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.