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Finding the Fourth Proportional to 505.30, 697.20 and 387.40

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Solution

The fourth proportional to 505.30, 697.20 and 387.40 is: 534.52

Step by Step Solution

  1. Step 1: Write the proportion equation
    505.30 : 697.20 = 387.40 : x
  2. Step 2: Convert to fraction form
    505.30/697.20 = 387.40/x
  3. Step 3: Cross multiply
    505.30x = 697.20 × 387.40
  4. Step 4: Simplify right side
    505.30x = 270,095.28
  5. Step 5: Solve for x
    x = 270,095.28/505.30
  6. Step 6: Final answer
    x = 534.52

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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.