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Finding the Fourth Proportional to 520.40, 718.10 and 287.51

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Solution

The fourth proportional to 520.40, 718.10 and 287.51 is: 396.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    520.40 : 718.10 = 287.51 : x
  2. Step 2: Convert to fraction form
    520.40/718.10 = 287.51/x
  3. Step 3: Cross multiply
    520.40x = 718.10 × 287.51
  4. Step 4: Simplify right side
    520.40x = 206,460.93
  5. Step 5: Solve for x
    x = 206,460.93/520.40
  6. Step 6: Final answer
    x = 396.74

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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.