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Finding the Fourth Proportional to 715.98, 987.96 and 421.23

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Solution

The fourth proportional to 715.98, 987.96 and 421.23 is: 581.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    715.98 : 987.96 = 421.23 : x
  2. Step 2: Convert to fraction form
    715.98/987.96 = 421.23/x
  3. Step 3: Cross multiply
    715.98x = 987.96 × 421.23
  4. Step 4: Simplify right side
    715.98x = 416,158.39
  5. Step 5: Solve for x
    x = 416,158.39/715.98
  6. Step 6: Final answer
    x = 581.24

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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.