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Finding the Fourth Proportional to 659.78, 910.78 and 397.76

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Solution

The fourth proportional to 659.78, 910.78 and 397.76 is: 549.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    659.78 : 910.78 = 397.76 : x
  2. Step 2: Convert to fraction form
    659.78/910.78 = 397.76/x
  3. Step 3: Cross multiply
    659.78x = 910.78 × 397.76
  4. Step 4: Simplify right side
    659.78x = 362,271.85
  5. Step 5: Solve for x
    x = 362,271.85/659.78
  6. Step 6: Final answer
    x = 549.08

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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.