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Finding the Fourth Proportional to 485.76, 728.55 and 312.15

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Solution

The fourth proportional to 485.76, 728.55 and 312.15 is: 468.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    485.76 : 728.55 = 312.15 : x
  2. Step 2: Convert to fraction form
    485.76/728.55 = 312.15/x
  3. Step 3: Cross multiply
    485.76x = 728.55 × 312.15
  4. Step 4: Simplify right side
    485.76x = 227,416.88
  5. Step 5: Solve for x
    x = 227,416.88/485.76
  6. Step 6: Final answer
    x = 468.17

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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.