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Finding the Fourth Proportional to 872.50, 1,308.78 and 287.32

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Solution

The fourth proportional to 872.50, 1,308.78 and 287.32 is: 430.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    872.50 : 1,308.78 = 287.32 : x
  2. Step 2: Convert to fraction form
    872.50/1,308.78 = 287.32/x
  3. Step 3: Cross multiply
    872.50x = 1,308.78 × 287.32
  4. Step 4: Simplify right side
    872.50x = 376,038.67
  5. Step 5: Solve for x
    x = 376,038.67/872.50
  6. Step 6: Final answer
    x = 430.99

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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.