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Finding the Fourth Proportional to 870.64, 1,306.74 and 408.68

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Solution

The fourth proportional to 870.64, 1,306.74 and 408.68 is: 613.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    870.64 : 1,306.74 = 408.68 : x
  2. Step 2: Convert to fraction form
    870.64/1,306.74 = 408.68/x
  3. Step 3: Cross multiply
    870.64x = 1,306.74 × 408.68
  4. Step 4: Simplify right side
    870.64x = 534,038.50
  5. Step 5: Solve for x
    x = 534,038.50/870.64
  6. Step 6: Final answer
    x = 613.39

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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.