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Finding the Fourth Proportional to 318.66, 477.30 and 208.70

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Solution

The fourth proportional to 318.66, 477.30 and 208.70 is: 312.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    318.66 : 477.30 = 208.70 : x
  2. Step 2: Convert to fraction form
    318.66/477.30 = 208.70/x
  3. Step 3: Cross multiply
    318.66x = 477.30 × 208.70
  4. Step 4: Simplify right side
    318.66x = 99,612.51
  5. Step 5: Solve for x
    x = 99,612.51/318.66
  6. Step 6: Final answer
    x = 312.60

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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.