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Finding the Fourth Proportional to 419.20, 581.60 and 386.80

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Solution

The fourth proportional to 419.20, 581.60 and 386.80 is: 536.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    419.20 : 581.60 = 386.80 : x
  2. Step 2: Convert to fraction form
    419.20/581.60 = 386.80/x
  3. Step 3: Cross multiply
    419.20x = 581.60 × 386.80
  4. Step 4: Simplify right side
    419.20x = 224,962.88
  5. Step 5: Solve for x
    x = 224,962.88/419.20
  6. Step 6: Final answer
    x = 536.65

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Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.