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Finding the Fourth Proportional to 420.58, 631.10 and 318.50

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Solution

The fourth proportional to 420.58, 631.10 and 318.50 is: 477.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.58 : 631.10 = 318.50 : x
  2. Step 2: Convert to fraction form
    420.58/631.10 = 318.50/x
  3. Step 3: Cross multiply
    420.58x = 631.10 × 318.50
  4. Step 4: Simplify right side
    420.58x = 201,005.35
  5. Step 5: Solve for x
    x = 201,005.35/420.58
  6. Step 6: Final answer
    x = 477.92

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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.