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Finding the Fourth Proportional to 879.60, 1,319.40 and 515.10

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Solution

The fourth proportional to 879.60, 1,319.40 and 515.10 is: 772.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    879.60 : 1,319.40 = 515.10 : x
  2. Step 2: Convert to fraction form
    879.60/1,319.40 = 515.10/x
  3. Step 3: Cross multiply
    879.60x = 1,319.40 × 515.10
  4. Step 4: Simplify right side
    879.60x = 679,622.94
  5. Step 5: Solve for x
    x = 679,622.94/879.60
  6. Step 6: Final answer
    x = 772.65

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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.