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Finding the Fourth Proportional to 615.47, 922.43 and 420.15

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Solution

The fourth proportional to 615.47, 922.43 and 420.15 is: 629.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    615.47 : 922.43 = 420.15 : x
  2. Step 2: Convert to fraction form
    615.47/922.43 = 420.15/x
  3. Step 3: Cross multiply
    615.47x = 922.43 × 420.15
  4. Step 4: Simplify right side
    615.47x = 387,556.86
  5. Step 5: Solve for x
    x = 387,556.86/615.47
  6. Step 6: Final answer
    x = 629.70

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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.