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Finding the Fourth Proportional to 498.75, 687.99 and 312.15

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Solution

The fourth proportional to 498.75, 687.99 and 312.15 is: 430.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    498.75 : 687.99 = 312.15 : x
  2. Step 2: Convert to fraction form
    498.75/687.99 = 312.15/x
  3. Step 3: Cross multiply
    498.75x = 687.99 × 312.15
  4. Step 4: Simplify right side
    498.75x = 214,756.08
  5. Step 5: Solve for x
    x = 214,756.08/498.75
  6. Step 6: Final answer
    x = 430.59

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.