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Finding the Fourth Proportional to 1,319.70, 1,976.64 and 771.30

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Solution

The fourth proportional to 1,319.70, 1,976.64 and 771.30 is: 1,155.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,319.70 : 1,976.64 = 771.30 : x
  2. Step 2: Convert to fraction form
    1,319.70/1,976.64 = 771.30/x
  3. Step 3: Cross multiply
    1,319.70x = 1,976.64 × 771.30
  4. Step 4: Simplify right side
    1,319.70x = 1,524,582.43
  5. Step 5: Solve for x
    x = 1,524,582.43/1,319.70
  6. Step 6: Final answer
    x = 1,155.25

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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.