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Finding the Fourth Proportional to 431.86, 647.80 and 260.50

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Solution

The fourth proportional to 431.86, 647.80 and 260.50 is: 390.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    431.86 : 647.80 = 260.50 : x
  2. Step 2: Convert to fraction form
    431.86/647.80 = 260.50/x
  3. Step 3: Cross multiply
    431.86x = 647.80 × 260.50
  4. Step 4: Simplify right side
    431.86x = 168,751.90
  5. Step 5: Solve for x
    x = 168,751.90/431.86
  6. Step 6: Final answer
    x = 390.76

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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.