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Finding the Fourth Proportional to 521.13, 781.30 and 315.65

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Solution

The fourth proportional to 521.13, 781.30 and 315.65 is: 473.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    521.13 : 781.30 = 315.65 : x
  2. Step 2: Convert to fraction form
    521.13/781.30 = 315.65/x
  3. Step 3: Cross multiply
    521.13x = 781.30 × 315.65
  4. Step 4: Simplify right side
    521.13x = 246,613.83
  5. Step 5: Solve for x
    x = 246,613.83/521.13
  6. Step 6: Final answer
    x = 473.23

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.