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Finding the Fourth Proportional to 771.72, 1,064.42 and 491.67

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Solution

The fourth proportional to 771.72, 1,064.42 and 491.67 is: 678.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    771.72 : 1,064.42 = 491.67 : x
  2. Step 2: Convert to fraction form
    771.72/1,064.42 = 491.67/x
  3. Step 3: Cross multiply
    771.72x = 1,064.42 × 491.67
  4. Step 4: Simplify right side
    771.72x = 523,338.06
  5. Step 5: Solve for x
    x = 523,338.06/771.72
  6. Step 6: Final answer
    x = 678.14

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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.