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Finding the Fourth Proportional to 720.91, 995.31 and 499.78

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Solution

The fourth proportional to 720.91, 995.31 and 499.78 is: 690.01

Step by Step Solution

  1. Step 1: Write the proportion equation
    720.91 : 995.31 = 499.78 : x
  2. Step 2: Convert to fraction form
    720.91/995.31 = 499.78/x
  3. Step 3: Cross multiply
    720.91x = 995.31 × 499.78
  4. Step 4: Simplify right side
    720.91x = 497,428.56
  5. Step 5: Solve for x
    x = 497,428.56/720.91
  6. Step 6: Final answer
    x = 690.01

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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.