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Finding the Fourth Proportional to 688.50, 947.34 and 664.56

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Solution

The fourth proportional to 688.50, 947.34 and 664.56 is: 914.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    688.50 : 947.34 = 664.56 : x
  2. Step 2: Convert to fraction form
    688.50/947.34 = 664.56/x
  3. Step 3: Cross multiply
    688.50x = 947.34 × 664.56
  4. Step 4: Simplify right side
    688.50x = 629,564.27
  5. Step 5: Solve for x
    x = 629,564.27/688.50
  6. Step 6: Final answer
    x = 914.40

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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.