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Finding the Fourth Proportional to 1,078.32, 1,618.70 and 429.51

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Solution

The fourth proportional to 1,078.32, 1,618.70 and 429.51 is: 644.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,078.32 : 1,618.70 = 429.51 : x
  2. Step 2: Convert to fraction form
    1,078.32/1,618.70 = 429.51/x
  3. Step 3: Cross multiply
    1,078.32x = 1,618.70 × 429.51
  4. Step 4: Simplify right side
    1,078.32x = 695,247.84
  5. Step 5: Solve for x
    x = 695,247.84/1,078.32
  6. Step 6: Final answer
    x = 644.75

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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.