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Finding the Fourth Proportional to 715.17, 986.61 and 420.30

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Solution

The fourth proportional to 715.17, 986.61 and 420.30 is: 579.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    715.17 : 986.61 = 420.30 : x
  2. Step 2: Convert to fraction form
    715.17/986.61 = 420.30/x
  3. Step 3: Cross multiply
    715.17x = 986.61 × 420.30
  4. Step 4: Simplify right side
    715.17x = 414,672.18
  5. Step 5: Solve for x
    x = 414,672.18/715.17
  6. Step 6: Final answer
    x = 579.82

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.