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Finding the Fourth Proportional to 642.60, 964.40 and 436.68

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Solution

The fourth proportional to 642.60, 964.40 and 436.68 is: 655.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.60 : 964.40 = 436.68 : x
  2. Step 2: Convert to fraction form
    642.60/964.40 = 436.68/x
  3. Step 3: Cross multiply
    642.60x = 964.40 × 436.68
  4. Step 4: Simplify right side
    642.60x = 421,134.19
  5. Step 5: Solve for x
    x = 421,134.19/642.60
  6. Step 6: Final answer
    x = 655.36

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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.