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Finding the Fourth Proportional to 898.16, 1,239.40 and 499.80

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Solution

The fourth proportional to 898.16, 1,239.40 and 499.80 is: 689.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    898.16 : 1,239.40 = 499.80 : x
  2. Step 2: Convert to fraction form
    898.16/1,239.40 = 499.80/x
  3. Step 3: Cross multiply
    898.16x = 1,239.40 × 499.80
  4. Step 4: Simplify right side
    898.16x = 619,443.42
  5. Step 5: Solve for x
    x = 619,443.42/898.16
  6. Step 6: Final answer
    x = 689.68

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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.