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Finding the Fourth Proportional to 987.01, 1,479.53 and 640.57

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Solution

The fourth proportional to 987.01, 1,479.53 and 640.57 is: 960.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    987.01 : 1,479.53 = 640.57 : x
  2. Step 2: Convert to fraction form
    987.01/1,479.53 = 640.57/x
  3. Step 3: Cross multiply
    987.01x = 1,479.53 × 640.57
  4. Step 4: Simplify right side
    987.01x = 947,739.33
  5. Step 5: Solve for x
    x = 947,739.33/987.01
  6. Step 6: Final answer
    x = 960.21

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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.