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Finding the Fourth Proportional to 661.06, 991.50 and 386.74

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Solution

The fourth proportional to 661.06, 991.50 and 386.74 is: 580.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.06 : 991.50 = 386.74 : x
  2. Step 2: Convert to fraction form
    661.06/991.50 = 386.74/x
  3. Step 3: Cross multiply
    661.06x = 991.50 × 386.74
  4. Step 4: Simplify right side
    661.06x = 383,452.71
  5. Step 5: Solve for x
    x = 383,452.71/661.06
  6. Step 6: Final answer
    x = 580.06

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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.