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Finding the Fourth Proportional to 312.80, 469.20 and 264.20

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Solution

The fourth proportional to 312.80, 469.20 and 264.20 is: 396.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    312.80 : 469.20 = 264.20 : x
  2. Step 2: Convert to fraction form
    312.80/469.20 = 264.20/x
  3. Step 3: Cross multiply
    312.80x = 469.20 × 264.20
  4. Step 4: Simplify right side
    312.80x = 123,962.64
  5. Step 5: Solve for x
    x = 123,962.64/312.80
  6. Step 6: Final answer
    x = 396.30

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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.