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Finding the Fourth Proportional to 465.90, 642.78 and 355.20

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Solution

The fourth proportional to 465.90, 642.78 and 355.20 is: 490.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    465.90 : 642.78 = 355.20 : x
  2. Step 2: Convert to fraction form
    465.90/642.78 = 355.20/x
  3. Step 3: Cross multiply
    465.90x = 642.78 × 355.20
  4. Step 4: Simplify right side
    465.90x = 228,315.46
  5. Step 5: Solve for x
    x = 228,315.46/465.90
  6. Step 6: Final answer
    x = 490.05

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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.