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Finding the Fourth Proportional to 493.80, 681.60 and 319.20

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Solution

The fourth proportional to 493.80, 681.60 and 319.20 is: 440.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    493.80 : 681.60 = 319.20 : x
  2. Step 2: Convert to fraction form
    493.80/681.60 = 319.20/x
  3. Step 3: Cross multiply
    493.80x = 681.60 × 319.20
  4. Step 4: Simplify right side
    493.80x = 217,566.72
  5. Step 5: Solve for x
    x = 217,566.72/493.80
  6. Step 6: Final answer
    x = 440.60

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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.