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Finding the Fourth Proportional to 409.50, 612.96 and 287.40

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Solution

The fourth proportional to 409.50, 612.96 and 287.40 is: 430.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    409.50 : 612.96 = 287.40 : x
  2. Step 2: Convert to fraction form
    409.50/612.96 = 287.40/x
  3. Step 3: Cross multiply
    409.50x = 612.96 × 287.40
  4. Step 4: Simplify right side
    409.50x = 176,164.70
  5. Step 5: Solve for x
    x = 176,164.70/409.50
  6. Step 6: Final answer
    x = 430.19

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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.