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Finding the Fourth Proportional to 420.76, 630.78 and 170.56

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Solution

The fourth proportional to 420.76, 630.78 and 170.56 is: 255.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.76 : 630.78 = 170.56 : x
  2. Step 2: Convert to fraction form
    420.76/630.78 = 170.56/x
  3. Step 3: Cross multiply
    420.76x = 630.78 × 170.56
  4. Step 4: Simplify right side
    420.76x = 107,585.84
  5. Step 5: Solve for x
    x = 107,585.84/420.76
  6. Step 6: Final answer
    x = 255.69

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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.