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Finding the Fourth Proportional to 659.80, 909.78 and 561.88

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Solution

The fourth proportional to 659.80, 909.78 and 561.88 is: 774.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    659.80 : 909.78 = 561.88 : x
  2. Step 2: Convert to fraction form
    659.80/909.78 = 561.88/x
  3. Step 3: Cross multiply
    659.80x = 909.78 × 561.88
  4. Step 4: Simplify right side
    659.80x = 511,187.19
  5. Step 5: Solve for x
    x = 511,187.19/659.80
  6. Step 6: Final answer
    x = 774.76

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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.