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Finding the Fourth Proportional to 520.65, 718.47 and 287.76

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Solution

The fourth proportional to 520.65, 718.47 and 287.76 is: 397.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    520.65 : 718.47 = 287.76 : x
  2. Step 2: Convert to fraction form
    520.65/718.47 = 287.76/x
  3. Step 3: Cross multiply
    520.65x = 718.47 × 287.76
  4. Step 4: Simplify right side
    520.65x = 206,746.93
  5. Step 5: Solve for x
    x = 206,746.93/520.65
  6. Step 6: Final answer
    x = 397.09

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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.