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Finding the Fourth Proportional to 872.60, 1,307.99 and 287.45

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Solution

The fourth proportional to 872.60, 1,307.99 and 287.45 is: 430.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    872.60 : 1,307.99 = 287.45 : x
  2. Step 2: Convert to fraction form
    872.60/1,307.99 = 287.45/x
  3. Step 3: Cross multiply
    872.60x = 1,307.99 × 287.45
  4. Step 4: Simplify right side
    872.60x = 375,983.56
  5. Step 5: Solve for x
    x = 375,983.56/872.60
  6. Step 6: Final answer
    x = 430.88

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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.