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Finding the Fourth Proportional to 660.26, 990.08 and 386.42

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Solution

The fourth proportional to 660.26, 990.08 and 386.42 is: 579.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.26 : 990.08 = 386.42 : x
  2. Step 2: Convert to fraction form
    660.26/990.08 = 386.42/x
  3. Step 3: Cross multiply
    660.26x = 990.08 × 386.42
  4. Step 4: Simplify right side
    660.26x = 382,586.71
  5. Step 5: Solve for x
    x = 382,586.71/660.26
  6. Step 6: Final answer
    x = 579.45

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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.