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Finding the Fourth Proportional to 777.60, 1,165.79 and 430.72

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Solution

The fourth proportional to 777.60, 1,165.79 and 430.72 is: 645.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    777.60 : 1,165.79 = 430.72 : x
  2. Step 2: Convert to fraction form
    777.60/1,165.79 = 430.72/x
  3. Step 3: Cross multiply
    777.60x = 1,165.79 × 430.72
  4. Step 4: Simplify right side
    777.60x = 502,127.23
  5. Step 5: Solve for x
    x = 502,127.23/777.60
  6. Step 6: Final answer
    x = 645.74

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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.