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Finding the Fourth Proportional to 660.35, 989.78 and 313.20

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Solution

The fourth proportional to 660.35, 989.78 and 313.20 is: 469.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.35 : 989.78 = 313.20 : x
  2. Step 2: Convert to fraction form
    660.35/989.78 = 313.20/x
  3. Step 3: Cross multiply
    660.35x = 989.78 × 313.20
  4. Step 4: Simplify right side
    660.35x = 310,003.91
  5. Step 5: Solve for x
    x = 310,003.91/660.35
  6. Step 6: Final answer
    x = 469.45

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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.