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Finding the Fourth Proportional to 661.78, 913.80 and 429.31

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Solution

The fourth proportional to 661.78, 913.80 and 429.31 is: 592.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.78 : 913.80 = 429.31 : x
  2. Step 2: Convert to fraction form
    661.78/913.80 = 429.31/x
  3. Step 3: Cross multiply
    661.78x = 913.80 × 429.31
  4. Step 4: Simplify right side
    661.78x = 392,303.48
  5. Step 5: Solve for x
    x = 392,303.48/661.78
  6. Step 6: Final answer
    x = 592.80

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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.