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Finding the Fourth Proportional to 661.92, 913.29 and 399.89

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Solution

The fourth proportional to 661.92, 913.29 and 399.89 is: 551.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.92 : 913.29 = 399.89 : x
  2. Step 2: Convert to fraction form
    661.92/913.29 = 399.89/x
  3. Step 3: Cross multiply
    661.92x = 913.29 × 399.89
  4. Step 4: Simplify right side
    661.92x = 365,210.97
  5. Step 5: Solve for x
    x = 365,210.97/661.92
  6. Step 6: Final answer
    x = 551.74

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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.