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Finding the Fourth Proportional to 470.50, 705.79 and 128.50

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Solution

The fourth proportional to 470.50, 705.79 and 128.50 is: 192.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    470.50 : 705.79 = 128.50 : x
  2. Step 2: Convert to fraction form
    470.50/705.79 = 128.50/x
  3. Step 3: Cross multiply
    470.50x = 705.79 × 128.50
  4. Step 4: Simplify right side
    470.50x = 90,694.02
  5. Step 5: Solve for x
    x = 90,694.02/470.50
  6. Step 6: Final answer
    x = 192.76

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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.