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Finding the Fourth Proportional to 491.12, 677.64 and 387.92

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Solution

The fourth proportional to 491.12, 677.64 and 387.92 is: 535.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    491.12 : 677.64 = 387.92 : x
  2. Step 2: Convert to fraction form
    491.12/677.64 = 387.92/x
  3. Step 3: Cross multiply
    491.12x = 677.64 × 387.92
  4. Step 4: Simplify right side
    491.12x = 262,870.11
  5. Step 5: Solve for x
    x = 262,870.11/491.12
  6. Step 6: Final answer
    x = 535.25

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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.