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Finding the Fourth Proportional to 891.78, 1,230.65 and 498.80

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Solution

The fourth proportional to 891.78, 1,230.65 and 498.80 is: 688.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    891.78 : 1,230.65 = 498.80 : x
  2. Step 2: Convert to fraction form
    891.78/1,230.65 = 498.80/x
  3. Step 3: Cross multiply
    891.78x = 1,230.65 × 498.80
  4. Step 4: Simplify right side
    891.78x = 613,846.56
  5. Step 5: Solve for x
    x = 613,846.56/891.78
  6. Step 6: Final answer
    x = 688.34

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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.