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Finding the Fourth Proportional to 521, 781.28 and 277.40

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Solution

The fourth proportional to 521, 781.28 and 277.40 is: 415.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    521 : 781.28 = 277.40 : x
  2. Step 2: Convert to fraction form
    521/781.28 = 277.40/x
  3. Step 3: Cross multiply
    521x = 781.28 × 277.40
  4. Step 4: Simplify right side
    521x = 216,727.07
  5. Step 5: Solve for x
    x = 216,727.07/521
  6. Step 6: Final answer
    x = 415.98

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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.