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Finding the Fourth Proportional to 660.61, 989.70 and 386.63

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Solution

The fourth proportional to 660.61, 989.70 and 386.63 is: 579.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.61 : 989.70 = 386.63 : x
  2. Step 2: Convert to fraction form
    660.61/989.70 = 386.63/x
  3. Step 3: Cross multiply
    660.61x = 989.70 × 386.63
  4. Step 4: Simplify right side
    660.61x = 382,647.71
  5. Step 5: Solve for x
    x = 382,647.71/660.61
  6. Step 6: Final answer
    x = 579.23

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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.