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Finding the Fourth Proportional to 891.80, 1,230.72 and 498.86

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Solution

The fourth proportional to 891.80, 1,230.72 and 498.86 is: 688.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    891.80 : 1,230.72 = 498.86 : x
  2. Step 2: Convert to fraction form
    891.80/1,230.72 = 498.86/x
  3. Step 3: Cross multiply
    891.80x = 1,230.72 × 498.86
  4. Step 4: Simplify right side
    891.80x = 613,956.98
  5. Step 5: Solve for x
    x = 613,956.98/891.80
  6. Step 6: Final answer
    x = 688.45

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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.