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Finding the Fourth Proportional to 670.12, 1,005.40 and 280.16

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Solution

The fourth proportional to 670.12, 1,005.40 and 280.16 is: 420.33

Step by Step Solution

  1. Step 1: Write the proportion equation
    670.12 : 1,005.40 = 280.16 : x
  2. Step 2: Convert to fraction form
    670.12/1,005.40 = 280.16/x
  3. Step 3: Cross multiply
    670.12x = 1,005.40 × 280.16
  4. Step 4: Simplify right side
    670.12x = 281,672.86
  5. Step 5: Solve for x
    x = 281,672.86/670.12
  6. Step 6: Final answer
    x = 420.33

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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.