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Finding the Fourth Proportional to 1,686.32, 2,530.40 and 1,278

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Solution

The fourth proportional to 1,686.32, 2,530.40 and 1,278 is: 1,917.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,686.32 : 2,530.40 = 1,278 : x
  2. Step 2: Convert to fraction form
    1,686.32/2,530.40 = 1,278/x
  3. Step 3: Cross multiply
    1,686.32x = 2,530.40 × 1,278
  4. Step 4: Simplify right side
    1,686.32x = 3,233,851.20
  5. Step 5: Solve for x
    x = 3,233,851.20/1,686.32
  6. Step 6: Final answer
    x = 1,917.70

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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.