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Finding the Fourth Proportional to 642.76, 956.45 and 640.60

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Solution

The fourth proportional to 642.76, 956.45 and 640.60 is: 953.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.76 : 956.45 = 640.60 : x
  2. Step 2: Convert to fraction form
    642.76/956.45 = 640.60/x
  3. Step 3: Cross multiply
    642.76x = 956.45 × 640.60
  4. Step 4: Simplify right side
    642.76x = 612,701.87
  5. Step 5: Solve for x
    x = 612,701.87/642.76
  6. Step 6: Final answer
    x = 953.24

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.