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Finding the Fourth Proportional to 420.50, 631.08 and 215.06

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Solution

The fourth proportional to 420.50, 631.08 and 215.06 is: 322.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.50 : 631.08 = 215.06 : x
  2. Step 2: Convert to fraction form
    420.50/631.08 = 215.06/x
  3. Step 3: Cross multiply
    420.50x = 631.08 × 215.06
  4. Step 4: Simplify right side
    420.50x = 135,716.61
  5. Step 5: Solve for x
    x = 135,716.61/420.50
  6. Step 6: Final answer
    x = 322.75

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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.