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Finding the Fourth Proportional to 661.19, 912.35 and 381.38

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Solution

The fourth proportional to 661.19, 912.35 and 381.38 is: 526.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.19 : 912.35 = 381.38 : x
  2. Step 2: Convert to fraction form
    661.19/912.35 = 381.38/x
  3. Step 3: Cross multiply
    661.19x = 912.35 × 381.38
  4. Step 4: Simplify right side
    661.19x = 347,945.57
  5. Step 5: Solve for x
    x = 347,945.57/661.19
  6. Step 6: Final answer
    x = 526.25

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Half scale
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Double scale
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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.