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Finding the Fourth Proportional to 661.60, 912.55 and 486.64

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Solution

The fourth proportional to 661.60, 912.55 and 486.64 is: 671.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.60 : 912.55 = 486.64 : x
  2. Step 2: Convert to fraction form
    661.60/912.55 = 486.64/x
  3. Step 3: Cross multiply
    661.60x = 912.55 × 486.64
  4. Step 4: Simplify right side
    661.60x = 444,076.34
  5. Step 5: Solve for x
    x = 444,076.34/661.60
  6. Step 6: Final answer
    x = 671.22

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.