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Finding the Fourth Proportional to 715.29, 986.88 and 420.57

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Solution

The fourth proportional to 715.29, 986.88 and 420.57 is: 580.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    715.29 : 986.88 = 420.57 : x
  2. Step 2: Convert to fraction form
    715.29/986.88 = 420.57/x
  3. Step 3: Cross multiply
    715.29x = 986.88 × 420.57
  4. Step 4: Simplify right side
    715.29x = 415,052.12
  5. Step 5: Solve for x
    x = 415,052.12/715.29
  6. Step 6: Final answer
    x = 580.26

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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.