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Finding the Fourth Proportional to 687.51, 948.78 and 408.06

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Solution

The fourth proportional to 687.51, 948.78 and 408.06 is: 563.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    687.51 : 948.78 = 408.06 : x
  2. Step 2: Convert to fraction form
    687.51/948.78 = 408.06/x
  3. Step 3: Cross multiply
    687.51x = 948.78 × 408.06
  4. Step 4: Simplify right side
    687.51x = 387,159.17
  5. Step 5: Solve for x
    x = 387,159.17/687.51
  6. Step 6: Final answer
    x = 563.13

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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.