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Finding the Fourth Proportional to 457.51, 687.08 and 420.88

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Solution

The fourth proportional to 457.51, 687.08 and 420.88 is: 632.07

Step by Step Solution

  1. Step 1: Write the proportion equation
    457.51 : 687.08 = 420.88 : x
  2. Step 2: Convert to fraction form
    457.51/687.08 = 420.88/x
  3. Step 3: Cross multiply
    457.51x = 687.08 × 420.88
  4. Step 4: Simplify right side
    457.51x = 289,174.80
  5. Step 5: Solve for x
    x = 289,174.80/457.51
  6. Step 6: Final answer
    x = 632.07

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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.