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Finding the Fourth Proportional to 660.11, 985.86 and 561.56

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Solution

The fourth proportional to 660.11, 985.86 and 561.56 is: 838.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.11 : 985.86 = 561.56 : x
  2. Step 2: Convert to fraction form
    660.11/985.86 = 561.56/x
  3. Step 3: Cross multiply
    660.11x = 985.86 × 561.56
  4. Step 4: Simplify right side
    660.11x = 553,614.61
  5. Step 5: Solve for x
    x = 553,614.61/660.11
  6. Step 6: Final answer
    x = 838.68

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.