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Finding the Fourth Proportional to 505.40, 757.14 and 390.20

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Solution

The fourth proportional to 505.40, 757.14 and 390.20 is: 584.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    505.40 : 757.14 = 390.20 : x
  2. Step 2: Convert to fraction form
    505.40/757.14 = 390.20/x
  3. Step 3: Cross multiply
    505.40x = 757.14 × 390.20
  4. Step 4: Simplify right side
    505.40x = 295,436.03
  5. Step 5: Solve for x
    x = 295,436.03/505.40
  6. Step 6: Final answer
    x = 584.56

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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.