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Finding the Fourth Proportional to 669.38, 917.07 and 643.46

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Solution

The fourth proportional to 669.38, 917.07 and 643.46 is: 881.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    669.38 : 917.07 = 643.46 : x
  2. Step 2: Convert to fraction form
    669.38/917.07 = 643.46/x
  3. Step 3: Cross multiply
    669.38x = 917.07 × 643.46
  4. Step 4: Simplify right side
    669.38x = 590,094.64
  5. Step 5: Solve for x
    x = 590,094.64/669.38
  6. Step 6: Final answer
    x = 881.55

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.