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Finding the Fourth Proportional to 285.50, 428.28 and 131.40

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Solution

The fourth proportional to 285.50, 428.28 and 131.40 is: 197.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    285.50 : 428.28 = 131.40 : x
  2. Step 2: Convert to fraction form
    285.50/428.28 = 131.40/x
  3. Step 3: Cross multiply
    285.50x = 428.28 × 131.40
  4. Step 4: Simplify right side
    285.50x = 56,275.99
  5. Step 5: Solve for x
    x = 56,275.99/285.50
  6. Step 6: Final answer
    x = 197.11

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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.