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Finding the Fourth Proportional to 687, 947.64 and 521.04

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Solution

The fourth proportional to 687, 947.64 and 521.04 is: 718.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    687 : 947.64 = 521.04 : x
  2. Step 2: Convert to fraction form
    687/947.64 = 521.04/x
  3. Step 3: Cross multiply
    687x = 947.64 × 521.04
  4. Step 4: Simplify right side
    687x = 493,758.35
  5. Step 5: Solve for x
    x = 493,758.35/687
  6. Step 6: Final answer
    x = 718.72

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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.