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Finding the Fourth Proportional to 660.76, 911.58 and 398.68

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Solution

The fourth proportional to 660.76, 911.58 and 398.68 is: 550.02

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.76 : 911.58 = 398.68 : x
  2. Step 2: Convert to fraction form
    660.76/911.58 = 398.68/x
  3. Step 3: Cross multiply
    660.76x = 911.58 × 398.68
  4. Step 4: Simplify right side
    660.76x = 363,428.71
  5. Step 5: Solve for x
    x = 363,428.71/660.76
  6. Step 6: Final answer
    x = 550.02

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Find fourth proportional to 330.38, 455.79 and 199.34
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1.5x scale

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.