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Finding the Fourth Proportional to 661.76, 913.06 and 428.75

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Solution

The fourth proportional to 661.76, 913.06 and 428.75 is: 591.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.76 : 913.06 = 428.75 : x
  2. Step 2: Convert to fraction form
    661.76/913.06 = 428.75/x
  3. Step 3: Cross multiply
    661.76x = 913.06 × 428.75
  4. Step 4: Simplify right side
    661.76x = 391,474.48
  5. Step 5: Solve for x
    x = 391,474.48/661.76
  6. Step 6: Final answer
    x = 591.57

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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.