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Finding the Fourth Proportional to 660.34, 990.64 and 455

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Solution

The fourth proportional to 660.34, 990.64 and 455 is: 682.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.34 : 990.64 = 455 : x
  2. Step 2: Convert to fraction form
    660.34/990.64 = 455/x
  3. Step 3: Cross multiply
    660.34x = 990.64 × 455
  4. Step 4: Simplify right side
    660.34x = 450,741.20
  5. Step 5: Solve for x
    x = 450,741.20/660.34
  6. Step 6: Final answer
    x = 682.59

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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.