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Finding the Fourth Proportional to 715.49, 987.30 and 400.75

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Solution

The fourth proportional to 715.49, 987.30 and 400.75 is: 552.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    715.49 : 987.30 = 400.75 : x
  2. Step 2: Convert to fraction form
    715.49/987.30 = 400.75/x
  3. Step 3: Cross multiply
    715.49x = 987.30 × 400.75
  4. Step 4: Simplify right side
    715.49x = 395,660.48
  5. Step 5: Solve for x
    x = 395,660.48/715.49
  6. Step 6: Final answer
    x = 552.99

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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.