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Finding the Fourth Proportional to 499.71, 689.16 and 312.99

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Solution

The fourth proportional to 499.71, 689.16 and 312.99 is: 431.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    499.71 : 689.16 = 312.99 : x
  2. Step 2: Convert to fraction form
    499.71/689.16 = 312.99/x
  3. Step 3: Cross multiply
    499.71x = 689.16 × 312.99
  4. Step 4: Simplify right side
    499.71x = 215,700.19
  5. Step 5: Solve for x
    x = 215,700.19/499.71
  6. Step 6: Final answer
    x = 431.65

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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.