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Finding the Fourth Proportional to 415.80, 620.66 and 387.32

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Solution

The fourth proportional to 415.80, 620.66 and 387.32 is: 578.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    415.80 : 620.66 = 387.32 : x
  2. Step 2: Convert to fraction form
    415.80/620.66 = 387.32/x
  3. Step 3: Cross multiply
    415.80x = 620.66 × 387.32
  4. Step 4: Simplify right side
    415.80x = 240,394.03
  5. Step 5: Solve for x
    x = 240,394.03/415.80
  6. Step 6: Final answer
    x = 578.15

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.