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Finding the Fourth Proportional to 670.50, 1,005.84 and 345.78

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Solution

The fourth proportional to 670.50, 1,005.84 and 345.78 is: 518.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    670.50 : 1,005.84 = 345.78 : x
  2. Step 2: Convert to fraction form
    670.50/1,005.84 = 345.78/x
  3. Step 3: Cross multiply
    670.50x = 1,005.84 × 345.78
  4. Step 4: Simplify right side
    670.50x = 347,799.36
  5. Step 5: Solve for x
    x = 347,799.36/670.50
  6. Step 6: Final answer
    x = 518.72

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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.