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Finding the Fourth Proportional to 661.39, 912.34 and 428.52

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Solution

The fourth proportional to 661.39, 912.34 and 428.52 is: 591.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.39 : 912.34 = 428.52 : x
  2. Step 2: Convert to fraction form
    661.39/912.34 = 428.52/x
  3. Step 3: Cross multiply
    661.39x = 912.34 × 428.52
  4. Step 4: Simplify right side
    661.39x = 390,955.94
  5. Step 5: Solve for x
    x = 390,955.94/661.39
  6. Step 6: Final answer
    x = 591.11

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Double scale
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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.