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Finding the Fourth Proportional to 987.04, 1,479.64 and 438.77

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Solution

The fourth proportional to 987.04, 1,479.64 and 438.77 is: 657.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    987.04 : 1,479.64 = 438.77 : x
  2. Step 2: Convert to fraction form
    987.04/1,479.64 = 438.77/x
  3. Step 3: Cross multiply
    987.04x = 1,479.64 × 438.77
  4. Step 4: Simplify right side
    987.04x = 649,217.98
  5. Step 5: Solve for x
    x = 649,217.98/987.04
  6. Step 6: Final answer
    x = 657.75

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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.