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Finding the Fourth Proportional to 771.79, 1,065.10 and 440.21

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Solution

The fourth proportional to 771.79, 1,065.10 and 440.21 is: 607.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    771.79 : 1,065.10 = 440.21 : x
  2. Step 2: Convert to fraction form
    771.79/1,065.10 = 440.21/x
  3. Step 3: Cross multiply
    771.79x = 1,065.10 × 440.21
  4. Step 4: Simplify right side
    771.79x = 468,865.47
  5. Step 5: Solve for x
    x = 468,865.47/771.79
  6. Step 6: Final answer
    x = 607.50

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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.