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Finding the Fourth Proportional to 670.57, 1,005.89 and 208.40

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Solution

The fourth proportional to 670.57, 1,005.89 and 208.40 is: 312.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    670.57 : 1,005.89 = 208.40 : x
  2. Step 2: Convert to fraction form
    670.57/1,005.89 = 208.40/x
  3. Step 3: Cross multiply
    670.57x = 1,005.89 × 208.40
  4. Step 4: Simplify right side
    670.57x = 209,621.40
  5. Step 5: Solve for x
    x = 209,621.40/670.57
  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.