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Finding the Fourth Proportional to 687.84, 947.98 and 521.64

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Solution

The fourth proportional to 687.84, 947.98 and 521.64 is: 718.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    687.84 : 947.98 = 521.64 : x
  2. Step 2: Convert to fraction form
    687.84/947.98 = 521.64/x
  3. Step 3: Cross multiply
    687.84x = 947.98 × 521.64
  4. Step 4: Simplify right side
    687.84x = 494,504.29
  5. Step 5: Solve for x
    x = 494,504.29/687.84
  6. Step 6: Final answer
    x = 718.92

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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.