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Finding the Fourth Proportional to 715.55, 987.44 and 405.05

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Solution

The fourth proportional to 715.55, 987.44 and 405.05 is: 558.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    715.55 : 987.44 = 405.05 : x
  2. Step 2: Convert to fraction form
    715.55/987.44 = 405.05/x
  3. Step 3: Cross multiply
    715.55x = 987.44 × 405.05
  4. Step 4: Simplify right side
    715.55x = 399,962.57
  5. Step 5: Solve for x
    x = 399,962.57/715.55
  6. Step 6: Final answer
    x = 558.96

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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.