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Finding the Fourth Proportional to 715.79, 987.71 and 401.06

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Solution

The fourth proportional to 715.79, 987.71 and 401.06 is: 553.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    715.79 : 987.71 = 401.06 : x
  2. Step 2: Convert to fraction form
    715.79/987.71 = 401.06/x
  3. Step 3: Cross multiply
    715.79x = 987.71 × 401.06
  4. Step 4: Simplify right side
    715.79x = 396,131.44
  5. Step 5: Solve for x
    x = 396,131.44/715.79
  6. Step 6: Final answer
    x = 553.42

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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.