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Finding the Fourth Proportional to 420.91, 631.16 and 157.18

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Solution

The fourth proportional to 420.91, 631.16 and 157.18 is: 235.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.91 : 631.16 = 157.18 : x
  2. Step 2: Convert to fraction form
    420.91/631.16 = 157.18/x
  3. Step 3: Cross multiply
    420.91x = 631.16 × 157.18
  4. Step 4: Simplify right side
    420.91x = 99,205.73
  5. Step 5: Solve for x
    x = 99,205.73/420.91
  6. Step 6: Final answer
    x = 235.69

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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.