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Finding the Fourth Proportional to 870.88, 1,306.50 and 459.79

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Solution

The fourth proportional to 870.88, 1,306.50 and 459.79 is: 689.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    870.88 : 1,306.50 = 459.79 : x
  2. Step 2: Convert to fraction form
    870.88/1,306.50 = 459.79/x
  3. Step 3: Cross multiply
    870.88x = 1,306.50 × 459.79
  4. Step 4: Simplify right side
    870.88x = 600,715.64
  5. Step 5: Solve for x
    x = 600,715.64/870.88
  6. Step 6: Final answer
    x = 689.78

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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.