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Finding the Fourth Proportional to 831.20, 1,146.80 and 499.46

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Solution

The fourth proportional to 831.20, 1,146.80 and 499.46 is: 689.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    831.20 : 1,146.80 = 499.46 : x
  2. Step 2: Convert to fraction form
    831.20/1,146.80 = 499.46/x
  3. Step 3: Cross multiply
    831.20x = 1,146.80 × 499.46
  4. Step 4: Simplify right side
    831.20x = 572,780.73
  5. Step 5: Solve for x
    x = 572,780.73/831.20
  6. Step 6: Final answer
    x = 689.10

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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.