Home / 1,398.38-1,929.80-768.87

Finding the Fourth Proportional to 1,398.38, 1,929.80 and 768.87

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Solution

The fourth proportional to 1,398.38, 1,929.80 and 768.87 is: 1,061.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,398.38 : 1,929.80 = 768.87 : x
  2. Step 2: Convert to fraction form
    1,398.38/1,929.80 = 768.87/x
  3. Step 3: Cross multiply
    1,398.38x = 1,929.80 × 768.87
  4. Step 4: Simplify right side
    1,398.38x = 1,483,764.36
  5. Step 5: Solve for x
    x = 1,483,764.36/1,398.38
  6. Step 6: Final answer
    x = 1,061.06

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1.5x scale

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.