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Finding the Fourth Proportional to 789.78, 1,090.02 and 479.28

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Solution

The fourth proportional to 789.78, 1,090.02 and 479.28 is: 661.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    789.78 : 1,090.02 = 479.28 : x
  2. Step 2: Convert to fraction form
    789.78/1,090.02 = 479.28/x
  3. Step 3: Cross multiply
    789.78x = 1,090.02 × 479.28
  4. Step 4: Simplify right side
    789.78x = 522,424.79
  5. Step 5: Solve for x
    x = 522,424.79/789.78
  6. Step 6: Final answer
    x = 661.48

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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.