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Finding the Fourth Proportional to 457.50, 685.14 and 420.12

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Solution

The fourth proportional to 457.50, 685.14 and 420.12 is: 629.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    457.50 : 685.14 = 420.12 : x
  2. Step 2: Convert to fraction form
    457.50/685.14 = 420.12/x
  3. Step 3: Cross multiply
    457.50x = 685.14 × 420.12
  4. Step 4: Simplify right side
    457.50x = 287,841.02
  5. Step 5: Solve for x
    x = 287,841.02/457.50
  6. Step 6: Final answer
    x = 629.16

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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.