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Finding the Fourth Proportional to 715.03, 986.28 and 420.09

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Solution

The fourth proportional to 715.03, 986.28 and 420.09 is: 579.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    715.03 : 986.28 = 420.09 : x
  2. Step 2: Convert to fraction form
    715.03/986.28 = 420.09/x
  3. Step 3: Cross multiply
    715.03x = 986.28 × 420.09
  4. Step 4: Simplify right side
    715.03x = 414,321.09
  5. Step 5: Solve for x
    x = 414,321.09/715.03
  6. Step 6: Final answer
    x = 579.45

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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.