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Finding the Fourth Proportional to 660.91, 991.71 and 387.53

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Solution

The fourth proportional to 660.91, 991.71 and 387.53 is: 581.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.91 : 991.71 = 387.53 : x
  2. Step 2: Convert to fraction form
    660.91/991.71 = 387.53/x
  3. Step 3: Cross multiply
    660.91x = 991.71 × 387.53
  4. Step 4: Simplify right side
    660.91x = 384,317.38
  5. Step 5: Solve for x
    x = 384,317.38/660.91
  6. Step 6: Final answer
    x = 581.50

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.