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Finding the Fourth Proportional to 660.30, 987.62 and 642.62

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Solution

The fourth proportional to 660.30, 987.62 and 642.62 is: 961.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.30 : 987.62 = 642.62 : x
  2. Step 2: Convert to fraction form
    660.30/987.62 = 642.62/x
  3. Step 3: Cross multiply
    660.30x = 987.62 × 642.62
  4. Step 4: Simplify right side
    660.30x = 634,656.21
  5. Step 5: Solve for x
    x = 634,656.21/660.30
  6. Step 6: Final answer
    x = 961.16

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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.