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Finding the Fourth Proportional to 398.40, 549.90 and 251.08

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Solution

The fourth proportional to 398.40, 549.90 and 251.08 is: 346.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    398.40 : 549.90 = 251.08 : x
  2. Step 2: Convert to fraction form
    398.40/549.90 = 251.08/x
  3. Step 3: Cross multiply
    398.40x = 549.90 × 251.08
  4. Step 4: Simplify right side
    398.40x = 138,068.89
  5. Step 5: Solve for x
    x = 138,068.89/398.40
  6. Step 6: Final answer
    x = 346.56

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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.