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Finding the Fourth Proportional to 421.18, 631.57 and 189.91

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Solution

The fourth proportional to 421.18, 631.57 and 189.91 is: 284.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.18 : 631.57 = 189.91 : x
  2. Step 2: Convert to fraction form
    421.18/631.57 = 189.91/x
  3. Step 3: Cross multiply
    421.18x = 631.57 × 189.91
  4. Step 4: Simplify right side
    421.18x = 119,941.10
  5. Step 5: Solve for x
    x = 119,941.10/421.18
  6. Step 6: Final answer
    x = 284.77

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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.