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Finding the Fourth Proportional to 660.21, 991.76 and 403.89

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Solution

The fourth proportional to 660.21, 991.76 and 403.89 is: 606.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.21 : 991.76 = 403.89 : x
  2. Step 2: Convert to fraction form
    660.21/991.76 = 403.89/x
  3. Step 3: Cross multiply
    660.21x = 991.76 × 403.89
  4. Step 4: Simplify right side
    660.21x = 400,559.93
  5. Step 5: Solve for x
    x = 400,559.93/660.21
  6. Step 6: Final answer
    x = 606.72

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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.