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Finding the Fourth Proportional to 640.72, 888.26 and 618.20

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Solution

The fourth proportional to 640.72, 888.26 and 618.20 is: 857.04

Step by Step Solution

  1. Step 1: Write the proportion equation
    640.72 : 888.26 = 618.20 : x
  2. Step 2: Convert to fraction form
    640.72/888.26 = 618.20/x
  3. Step 3: Cross multiply
    640.72x = 888.26 × 618.20
  4. Step 4: Simplify right side
    640.72x = 549,117.89
  5. Step 5: Solve for x
    x = 549,117.89/640.72
  6. Step 6: Final answer
    x = 857.04

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Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.