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Finding the Fourth Proportional to 528.78, 790.71 and 390.48

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Solution

The fourth proportional to 528.78, 790.71 and 390.48 is: 583.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    528.78 : 790.71 = 390.48 : x
  2. Step 2: Convert to fraction form
    528.78/790.71 = 390.48/x
  3. Step 3: Cross multiply
    528.78x = 790.71 × 390.48
  4. Step 4: Simplify right side
    528.78x = 308,756.44
  5. Step 5: Solve for x
    x = 308,756.44/528.78
  6. Step 6: Final answer
    x = 583.90

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.