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Finding the Fourth Proportional to 987.03, 1,479.15 and 621.60

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Solution

The fourth proportional to 987.03, 1,479.15 and 621.60 is: 931.52

Step by Step Solution

  1. Step 1: Write the proportion equation
    987.03 : 1,479.15 = 621.60 : x
  2. Step 2: Convert to fraction form
    987.03/1,479.15 = 621.60/x
  3. Step 3: Cross multiply
    987.03x = 1,479.15 × 621.60
  4. Step 4: Simplify right side
    987.03x = 919,439.64
  5. Step 5: Solve for x
    x = 919,439.64/987.03
  6. Step 6: Final answer
    x = 931.52

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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.