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Finding the Fourth Proportional to 312.64, 469.04 and 139.30

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Solution

The fourth proportional to 312.64, 469.04 and 139.30 is: 208.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    312.64 : 469.04 = 139.30 : x
  2. Step 2: Convert to fraction form
    312.64/469.04 = 139.30/x
  3. Step 3: Cross multiply
    312.64x = 469.04 × 139.30
  4. Step 4: Simplify right side
    312.64x = 65,336.58
  5. Step 5: Solve for x
    x = 65,336.58/312.64
  6. Step 6: Final answer
    x = 208.98

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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.