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Finding the Fourth Proportional to 645.76, 968.78 and 189.76

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Solution

The fourth proportional to 645.76, 968.78 and 189.76 is: 284.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    645.76 : 968.78 = 189.76 : x
  2. Step 2: Convert to fraction form
    645.76/968.78 = 189.76/x
  3. Step 3: Cross multiply
    645.76x = 968.78 × 189.76
  4. Step 4: Simplify right side
    645.76x = 183,835.69
  5. Step 5: Solve for x
    x = 183,835.69/645.76
  6. Step 6: Final answer
    x = 284.68

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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.