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Finding the Fourth Proportional to 660.38, 911.25 and 380.57

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Solution

The fourth proportional to 660.38, 911.25 and 380.57 is: 525.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.38 : 911.25 = 380.57 : x
  2. Step 2: Convert to fraction form
    660.38/911.25 = 380.57/x
  3. Step 3: Cross multiply
    660.38x = 911.25 × 380.57
  4. Step 4: Simplify right side
    660.38x = 346,789.86
  5. Step 5: Solve for x
    x = 346,789.86/660.38
  6. Step 6: Final answer
    x = 525.14

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Half scale
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Double scale
Find fourth proportional to 661.38, 912.63 and 381.57
Similar ratio
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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.