Home / 1,389.60-1,917.65-768.60

Finding the Fourth Proportional to 1,389.60, 1,917.65 and 768.60

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Solution

The fourth proportional to 1,389.60, 1,917.65 and 768.60 is: 1,060.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,389.60 : 1,917.65 = 768.60 : x
  2. Step 2: Convert to fraction form
    1,389.60/1,917.65 = 768.60/x
  3. Step 3: Cross multiply
    1,389.60x = 1,917.65 × 768.60
  4. Step 4: Simplify right side
    1,389.60x = 1,473,892.36
  5. Step 5: Solve for x
    x = 1,473,892.36/1,389.60
  6. Step 6: Final answer
    x = 1,060.66

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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.