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Finding the Fourth Proportional to 542.40, 812.40 and 419.70

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Solution

The fourth proportional to 542.40, 812.40 and 419.70 is: 628.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    542.40 : 812.40 = 419.70 : x
  2. Step 2: Convert to fraction form
    542.40/812.40 = 419.70/x
  3. Step 3: Cross multiply
    542.40x = 812.40 × 419.70
  4. Step 4: Simplify right side
    542.40x = 340,964.28
  5. Step 5: Solve for x
    x = 340,964.28/542.40
  6. Step 6: Final answer
    x = 628.62

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.