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Finding the Fourth Proportional to 677.29, 1,015.39 and 420.25

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Solution

The fourth proportional to 677.29, 1,015.39 and 420.25 is: 630.04

Step by Step Solution

  1. Step 1: Write the proportion equation
    677.29 : 1,015.39 = 420.25 : x
  2. Step 2: Convert to fraction form
    677.29/1,015.39 = 420.25/x
  3. Step 3: Cross multiply
    677.29x = 1,015.39 × 420.25
  4. Step 4: Simplify right side
    677.29x = 426,717.65
  5. Step 5: Solve for x
    x = 426,717.65/677.29
  6. Step 6: Final answer
    x = 630.04

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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.