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Finding the Fourth Proportional to 654.78, 903.66 and 392.80

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Solution

The fourth proportional to 654.78, 903.66 and 392.80 is: 542.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    654.78 : 903.66 = 392.80 : x
  2. Step 2: Convert to fraction form
    654.78/903.66 = 392.80/x
  3. Step 3: Cross multiply
    654.78x = 903.66 × 392.80
  4. Step 4: Simplify right side
    654.78x = 354,957.65
  5. Step 5: Solve for x
    x = 354,957.65/654.78
  6. Step 6: Final answer
    x = 542.10

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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.