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Finding the Fourth Proportional to 644.36, 888.70 and 420.02

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Solution

The fourth proportional to 644.36, 888.70 and 420.02 is: 579.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    644.36 : 888.70 = 420.02 : x
  2. Step 2: Convert to fraction form
    644.36/888.70 = 420.02/x
  3. Step 3: Cross multiply
    644.36x = 888.70 × 420.02
  4. Step 4: Simplify right side
    644.36x = 373,271.77
  5. Step 5: Solve for x
    x = 373,271.77/644.36
  6. Step 6: Final answer
    x = 579.29

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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.