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Finding the Fourth Proportional to 898.28, 1,239.54 and 499.90

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Solution

The fourth proportional to 898.28, 1,239.54 and 499.90 is: 689.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    898.28 : 1,239.54 = 499.90 : x
  2. Step 2: Convert to fraction form
    898.28/1,239.54 = 499.90/x
  3. Step 3: Cross multiply
    898.28x = 1,239.54 × 499.90
  4. Step 4: Simplify right side
    898.28x = 619,646.05
  5. Step 5: Solve for x
    x = 619,646.05/898.28
  6. Step 6: Final answer
    x = 689.81

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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.