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Finding the Fourth Proportional to 491.59, 678.14 and 398.44

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Solution

The fourth proportional to 491.59, 678.14 and 398.44 is: 549.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    491.59 : 678.14 = 398.44 : x
  2. Step 2: Convert to fraction form
    491.59/678.14 = 398.44/x
  3. Step 3: Cross multiply
    491.59x = 678.14 × 398.44
  4. Step 4: Simplify right side
    491.59x = 270,200.79
  5. Step 5: Solve for x
    x = 270,200.79/491.59
  6. Step 6: Final answer
    x = 549.64

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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.