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Finding the Fourth Proportional to 420.91, 631.43 and 143.32

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Solution

The fourth proportional to 420.91, 631.43 and 143.32 is: 215.00

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.91 : 631.43 = 143.32 : x
  2. Step 2: Convert to fraction form
    420.91/631.43 = 143.32/x
  3. Step 3: Cross multiply
    420.91x = 631.43 × 143.32
  4. Step 4: Simplify right side
    420.91x = 90,494.25
  5. Step 5: Solve for x
    x = 90,494.25/420.91
  6. Step 6: Final answer
    x = 215.00

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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.