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Finding the Fourth Proportional to 515.80, 773.70 and 386.20

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Solution

The fourth proportional to 515.80, 773.70 and 386.20 is: 579.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    515.80 : 773.70 = 386.20 : x
  2. Step 2: Convert to fraction form
    515.80/773.70 = 386.20/x
  3. Step 3: Cross multiply
    515.80x = 773.70 × 386.20
  4. Step 4: Simplify right side
    515.80x = 298,802.94
  5. Step 5: Solve for x
    x = 298,802.94/515.80
  6. Step 6: Final answer
    x = 579.30

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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.