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Finding the Fourth Proportional to 419.20, 577.12 and 389.76

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Solution

The fourth proportional to 419.20, 577.12 and 389.76 is: 536.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    419.20 : 577.12 = 389.76 : x
  2. Step 2: Convert to fraction form
    419.20/577.12 = 389.76/x
  3. Step 3: Cross multiply
    419.20x = 577.12 × 389.76
  4. Step 4: Simplify right side
    419.20x = 224,938.29
  5. Step 5: Solve for x
    x = 224,938.29/419.20
  6. Step 6: Final answer
    x = 536.59

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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.